-=cut
-Copyright (c) 1994-1996,1998-2001 Todd C. Miller <Todd.Miller@courtesan.com>
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
-
-1. Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
-
-2. Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in the
- documentation and/or other materials provided with the distribution.
-
-3. The name of the author may not be used to endorse or promote products
- derived from this software without specific prior written permission
- from the author.
-
-4. Products derived from this software may not be called "Sudo" nor
- may "Sudo" appear in their names without specific prior written
- permission from the author.
-
-THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
-INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
-AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
-THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
-OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
-OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+Copyright (c) 1994-1996, 1998-2005, 2007-2010
+ Todd C. Miller <Todd.Miller@courtesan.com>
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-$Sudo: sudoers.pod,v 1.63 2002/01/13 18:36:44 millert Exp $
+Sponsored in part by the Defense Advanced Research Projects
+Agency (DARPA) and Air Force Research Laboratory, Air Force
+Materiel Command, USAF, under agreement number F39502-99-1-0512.
+
=pod
=head1 NAME
=head1 DESCRIPTION
-The I<sudoers> file is composed of two types of entries:
-aliases (basically variables) and user specifications
-(which specify who may run what). The grammar of I<sudoers>
-will be described below in Extended Backus-Naur Form (EBNF).
-Don't despair if you don't know what EBNF is; it is fairly
-simple, and the definitions below are annotated.
+The I<sudoers> file is composed of two types of entries: aliases
+(basically variables) and user specifications (which specify who
+may run what).
+
+When multiple entries match for a user, they are applied in order.
+Where there are multiple matches, the last match is used (which is
+not necessarily the most specific match).
+
+The I<sudoers> grammar will be described below in Extended Backus-Naur
+Form (EBNF). Don't despair if you don't know what EBNF is; it is
+fairly simple, and the definitions below are annotated.
=head2 Quick guide to EBNF
expressions. Do not, however, confuse them with "wildcard"
characters, which have different meanings.
-=over 8
+=over 4
=item C<?>
where I<Alias_Type> is one of C<User_Alias>, C<Runas_Alias>, C<Host_Alias>,
or C<Cmnd_Alias>. A C<NAME> is a string of uppercase letters, numbers,
-and the underscore characters ('_'). A C<NAME> B<must> start with an
+and underscore characters ('_'). A C<NAME> B<must> start with an
uppercase letter. It is possible to put several alias definitions
of the same type on a single line, joined by a colon (':'). E.g.,
User_List ::= User |
User ',' User_List
- User ::= '!'* username |
+ User ::= '!'* user name |
+ '!'* '#'uid |
'!'* '%'group |
'!'* '+'netgroup |
+ '!'* '%:'nonunix_group |
'!'* User_Alias
-A C<User_List> is made up of one or more usernames, uids
-(prefixed with '#'), System groups (prefixed with '%'),
-netgroups (prefixed with '+') and other aliases. Each list
-item may be prefixed with one or more '!' operators. An odd number
-of '!' operators negate the value of the item; an even number
-just cancel each other out.
+A C<User_List> is made up of one or more user names, uids (prefixed
+with '#'), system groups (prefixed with '%'), netgroups (prefixed
+with '+') and C<User_Alias>es. Each list item may be prefixed with
+zero or more '!' operators. An odd number of '!' operators negate
+the value of the item; an even number just cancel each other out.
+
+A C<user name>, C<group>, C<netgroup> or C<nonunix_group> may
+be enclosed in double quotes to avoid the need for escaping special
+characters. Alternately, special characters may be specified in
+escaped hex mode, e.g. \x20 for space.
+
+The C<nonunix_group> syntax depends on the underlying implementation.
+For instance, the QAS AD backend supports the following formats:
+
+=over 4
+
+=item *
+
+Group in the same domain: "Group Name"
+
+=item *
+
+Group in any domain: "Group Name@FULLY.QUALIFIED.DOMAIN"
+
+=item *
- Runas_List ::= Runas_User |
- Runas_User ',' Runas_List
+Group SID: "S-1-2-34-5678901234-5678901234-5678901234-567"
- Runas_User ::= '!'* username |
- '!'* '#'uid |
- '!'* '%'group |
- '!'* +netgroup |
- '!'* Runas_Alias
+=back
+
+Note that quotes around group names are optional. Unquoted strings must
+use a backslash (\) to escape spaces and the '@' symbol.
+
+ Runas_List ::= Runas_Member |
+ Runas_Member ',' Runas_List
-A C<Runas_List> is similar to a C<User_List> except that it can
-also contain uids (prefixed with '#') and instead of C<User_Alias>es
-it can contain C<Runas_Alias>es.
+ Runas_Member ::= '!'* user name |
+ '!'* '#'uid |
+ '!'* '%'group |
+ '!'* +netgroup |
+ '!'* Runas_Alias
+
+A C<Runas_List> is similar to a C<User_List> except that instead
+of C<User_Alias>es it can contain C<Runas_Alias>es. Note that
+user names and groups are matched as strings. In other words, two
+users (groups) with the same uid (gid) are considered to be distinct.
+If you wish to match all user names with the same uid (e.g.E<nbsp>root
+and toor), you can use a uid instead (#0 in the example given).
Host_List ::= Host |
Host ',' Host_List
- Host ::= '!'* hostname |
+ Host ::= '!'* host name |
'!'* ip_addr |
'!'* network(/netmask)? |
'!'* '+'netgroup |
'!'* Host_Alias
-A C<Host_List> is made up of one or more hostnames, IP addresses,
+A C<Host_List> is made up of one or more host names, IP addresses,
network numbers, netgroups (prefixed with '+') and other aliases.
Again, the value of an item may be negated with the '!' operator.
-If you do not specify a netmask with a network number, the netmask
-of the host's ethernet interface(s) will be used when matching.
-The netmask may be specified either in dotted quad notation (e.g.
-255.255.255.0) or CIDR notation (number of bits, e.g. 24). A hostname
-may include shell-style wildcards (see `Wildcards' section below),
-but unless the C<hostname> command on your machine returns the fully
-qualified hostname, you'll need to use the I<fqdn> option for wildcards
-to be useful.
+If you do not specify a netmask along with the network number,
+B<sudo> will query each of the local host's network interfaces and,
+if the network number corresponds to one of the hosts's network
+interfaces, the corresponding netmask will be used. The netmask
+may be specified either in standard IP address notation
+(e.g.E<nbsp>255.255.255.0 or ffff:ffff:ffff:ffff::),
+or CIDR notation (number of bits, e.g.E<nbsp>24 or 64). A host name may
+include shell-style wildcards (see the L<Wildcards> section below),
+but unless the C<host name> command on your machine returns the fully
+qualified host name, you'll need to use the I<fqdn> option for
+wildcards to be useful. Note B<sudo> only inspects actual network
+interfaces; this means that IP address 127.0.0.1 (localhost) will
+never match. Also, the host name "localhost" will only match if
+that is the actual host name, which is usually only the case for
+non-networked systems.
Cmnd_List ::= Cmnd |
Cmnd ',' Cmnd_List
- commandname ::= filename |
- filename args |
- filename '""'
+ commandname ::= file name |
+ file name args |
+ file name '""'
Cmnd ::= '!'* commandname |
'!'* directory |
+ '!'* "sudoedit" |
'!'* Cmnd_Alias
A C<Cmnd_List> is a list of one or more commandnames, directories, and other
-aliases. A commandname is a fully qualified filename which may include
-shell-style wildcards (see `Wildcards' section below). A simple
-filename allows the user to run the command with any arguments he/she
+aliases. A commandname is a fully qualified file name which may include
+shell-style wildcards (see the L<Wildcards> section below). A simple
+file name allows the user to run the command with any arguments he/she
wishes. However, you may also specify command line arguments (including
wildcards). Alternately, you can specify C<""> to indicate that the command
may only be run B<without> command line arguments. A directory is a
-fully qualified pathname ending in a '/'. When you specify a directory
+fully qualified path name ending in a '/'. When you specify a directory
in a C<Cmnd_List>, the user will be able to run any file within that directory
(but not in any subdirectories therein).
in the C<Cmnd> must match exactly those given by the user on the command line
(or match the wildcards if there are any). Note that the following
characters must be escaped with a '\' if they are used in command
-arguments: ',', ':', '=', '\'.
+arguments: ',', ':', '=', '\'. The special command C<"sudoedit">
+is used to permit a user to run B<sudo> with the B<-e> option (or
+as B<sudoedit>). It may take command line arguments just as
+a normal command does.
=head2 Defaults
Certain configuration options may be changed from their default
values at runtime via one or more C<Default_Entry> lines. These
-may affect all users on any host, all users on a specific host,
-or just a specific user. When multiple entries match, they are
-applied in order. Where there are conflicting values, the last
-value on a matching line takes effect.
-
- Default_Type ::= 'Defaults' ||
- 'Defaults' ':' User ||
- 'Defaults' '@' Host
+may affect all users on any host, all users on a specific host, a
+specific user, a specific command, or commands being run as a specific user.
+Note that per-command entries may not include command line arguments.
+If you need to specify arguments, define a C<Cmnd_Alias> and reference
+that instead.
+
+ Default_Type ::= 'Defaults' |
+ 'Defaults' '@' Host_List |
+ 'Defaults' ':' User_List |
+ 'Defaults' '!' Cmnd_List |
+ 'Defaults' '>' Runas_List
Default_Entry ::= Default_Type Parameter_List
- Parameter ::= Parameter '=' Value ||
- Parameter '+=' Value ||
- Parameter '-=' Value ||
- '!'* Parameter ||
+ Parameter_List ::= Parameter |
+ Parameter ',' Parameter_List
+
+ Parameter ::= Parameter '=' Value |
+ Parameter '+=' Value |
+ Parameter '-=' Value |
+ '!'* Parameter
Parameters may be B<flags>, B<integer> values, B<strings>, or B<lists>.
Flags are implicitly boolean and can be turned off via the '!'
It is not an error to use the C<-=> operator to remove an element
that does not exist in a list.
-Note that since the I<sudoers> file is parsed in order the best place
-to put the Defaults section is after the Host, User, and Cmnd aliases
-but before the user specifications.
+Defaults entries are parsed in the following order: generic, host
+and user Defaults first, then runas Defaults and finally command
+defaults.
-B<Flags>:
+See L<"SUDOERS OPTIONS"> for a list of supported Defaults parameters.
-=over 12
+=head2 User Specification
-=item long_otp_prompt
+ User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \
+ (':' Host_List '=' Cmnd_Spec_List)*
-When validating with a One Time Password scheme (B<S/Key> or B<OPIE>),
-a two-line prompt is used to make it easier to cut and paste the
-challenge to a local window. It's not as pretty as the default but
-some people find it more convenient. This flag is I<@long_otp_prompt@>
-by default.
+ Cmnd_Spec_List ::= Cmnd_Spec |
+ Cmnd_Spec ',' Cmnd_Spec_List
-=item ignore_dot
+ Cmnd_Spec ::= Runas_Spec? SELinux_Spec? Tag_Spec* Cmnd
-If set, B<sudo> will ignore '.' or '' (current dir) in the C<PATH>
-environment variable; the C<PATH> itself is not modified. This
-flag is I<@ignore_dot@> by default.
+ Runas_Spec ::= '(' Runas_List? (':' Runas_List)? ')'
-=item mail_always
+ SELinux_Spec ::= ('ROLE=role' | 'TYPE=type')
-Send mail to the I<mailto> user every time a users runs B<sudo>.
-This flag is I<off> by default.
+ Tag_Spec ::= ('NOPASSWD:' | 'PASSWD:' | 'NOEXEC:' | 'EXEC:' |
+ 'SETENV:' | 'NOSETENV:' | 'LOG_INPUT:' | 'NOLOG_INPUT:' |
+ 'LOG_OUTPUT:' | 'NOLOG_OUTPUT:')
-=item mail_badpass
+A B<user specification> determines which commands a user may run
+(and as what user) on specified hosts. By default, commands are
+run as B<root>, but this can be changed on a per-command basis.
-Send mail to the I<mailto> user if the user running sudo does not
-enter the correct password. This flag is I<off> by default.
+The basic structure of a user specification is `who = where (as_whom)
+what'. Let's break that down into its constituent parts:
-=item mail_no_user
+=head2 Runas_Spec
-If set, mail will be sent to the I<mailto> user if the invoking
-user is not in the I<sudoers> file. This flag is I<@mail_no_user@>
-by default.
+A C<Runas_Spec> determines the user and/or the group that a command
+may be run as. A fully-specified C<Runas_Spec> consists of two
+C<Runas_List>s (as defined above) separated by a colon (':') and
+enclosed in a set of parentheses. The first C<Runas_List> indicates
+which users the command may be run as via B<sudo>'s B<-u> option.
+The second defines a list of groups that can be specified via
+B<sudo>'s B<-g> option. If both C<Runas_List>s are specified, the
+command may be run with any combination of users and groups listed
+in their respective C<Runas_List>s. If only the first is specified,
+the command may be run as any user in the list but no B<-g> option
+may be specified. If the first C<Runas_List> is empty but the
+second is specified, the command may be run as the invoking user
+with the group set to any listed in the C<Runas_List>. If no
+C<Runas_Spec> is specified the command may be run as B<root> and
+no group may be specified.
+
+A C<Runas_Spec> sets the default for the commands that follow it.
+What this means is that for the entry:
+
+ dgb boulder = (operator) /bin/ls, /bin/kill, /usr/bin/lprm
-=item mail_no_host
+The user B<dgb> may run F</bin/ls>, F</bin/kill>, and
+F</usr/bin/lprm> -- but only as B<operator>. E.g.,
-If set, mail will be sent to the I<mailto> user if the invoking
-user exists in the I<sudoers> file, but is not allowed to run
-commands on the current host. This flag is I<@mail_no_host@> by default.
+ $ sudo -u operator /bin/ls.
-=item mail_no_perms
+It is also possible to override a C<Runas_Spec> later on in an
+entry. If we modify the entry like so:
-If set, mail will be sent to the I<mailto> user if the invoking
-user allowed to use B<sudo> but the command they are trying is not
-listed in their I<sudoers> file entry. This flag is I<@mail_no_perms@>
-by default.
+ dgb boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm
-=item tty_tickets
+Then user B<dgb> is now allowed to run F</bin/ls> as B<operator>,
+but F</bin/kill> and F</usr/bin/lprm> as B<root>.
-If set, users must authenticate on a per-tty basis. Normally,
-B<sudo> uses a directory in the ticket dir with the same name as
-the user running it. With this flag enabled, B<sudo> will use a
-file named for the tty the user is logged in on in that directory.
-This flag is I<@tty_tickets@> by default.
+We can extend this to allow B<dgb> to run C</bin/ls> with either
+the user or group set to B<operator>:
-=item lecture
+ dgb boulder = (operator : operator) /bin/ls, (root) /bin/kill, \
+ /usr/bin/lprm
+
+In the following example, user B<tcm> may run commands that access
+a modem device file with the dialer group. Note that in this example
+only the group will be set, the command still runs as user B<tcm>.
+
+ tcm boulder = (:dialer) /usr/bin/tip, /usr/bin/cu, \
+ /usr/local/bin/minicom
+
+=head2 SELinux_Spec
+
+On systems with SELinux support, I<sudoers> entries may optionally have
+an SELinux role and/or type associated with a command. If a role or
+type is specified with the command it will override any default values
+specified in I<sudoers>. A role or type specified on the command line,
+however, will supercede the values in I<sudoers>.
+
+=head2 Tag_Spec
+
+A command may have zero or more tags associated with it. There are
+eight possible tag values, C<NOPASSWD>, C<PASSWD>, C<NOEXEC>,
+C<EXEC>, C<SETENV>, C<NOSETENV>, C<LOG_INPUT>, C<NOLOG_INPUT>,
+C<LOG_OUTPUT> and C<NOLOG_OUTPUT>. Once a tag is set on a C<Cmnd>,
+subsequent C<Cmnd>s in the C<Cmnd_Spec_List>, inherit the tag unless
+it is overridden by the opposite tag (i.e.: C<PASSWD> overrides
+C<NOPASSWD> and C<NOEXEC> overrides C<EXEC>).
+
+=head3 NOPASSWD and PASSWD
+
+By default, B<sudo> requires that a user authenticate him or herself
+before running a command. This behavior can be modified via the
+C<NOPASSWD> tag. Like a C<Runas_Spec>, the C<NOPASSWD> tag sets
+a default for the commands that follow it in the C<Cmnd_Spec_List>.
+Conversely, the C<PASSWD> tag can be used to reverse things.
+For example:
+
+ ray rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm
+
+would allow the user B<ray> to run F</bin/kill>, F</bin/ls>, and
+F</usr/bin/lprm> as B<root> on the machine rushmore without
+authenticating himself. If we only want B<ray> to be able to
+run F</bin/kill> without a password the entry would be:
+
+ ray rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm
+
+Note, however, that the C<PASSWD> tag has no effect on users who are
+in the group specified by the I<exempt_group> option.
+
+By default, if the C<NOPASSWD> tag is applied to any of the entries
+for a user on the current host, he or she will be able to run
+C<sudo -l> without a password. Additionally, a user may only run
+C<sudo -v> without a password if the C<NOPASSWD> tag is present
+for all a user's entries that pertain to the current host.
+This behavior may be overridden via the verifypw and listpw options.
+
+=head3 NOEXEC and EXEC
+
+If B<sudo> has been compiled with I<noexec> support and the underlying
+operating system supports it, the C<NOEXEC> tag can be used to prevent
+a dynamically-linked executable from running further commands itself.
+
+In the following example, user B<aaron> may run F</usr/bin/more>
+and F</usr/bin/vi> but shell escapes will be disabled.
+
+ aaron shanty = NOEXEC: /usr/bin/more, /usr/bin/vi
+
+See the L<PREVENTING SHELL ESCAPES> section below for more details
+on how C<NOEXEC> works and whether or not it will work on your system.
+
+=head3 SETENV and NOSETENV
+
+These tags override the value of the I<setenv> option on a per-command
+basis. Note that if C<SETENV> has been set for a command, any
+environment variables set on the command line way are not subject
+to the restrictions imposed by I<env_check>, I<env_delete>, or
+I<env_keep>. As such, only trusted users should be allowed to set
+variables in this manner. If the command matched is B<ALL>, the
+C<SETENV> tag is implied for that command; this default may
+be overridden by use of the C<NOSETENV> tag.
+
+=head3 LOG_INPUT and NOLOG_INPUT
+
+These tags override the value of the I<log_input> option on a
+per-command basis. For more information, see the description of
+I<log_input> in the L<"SUDOERS OPTIONS"> section below.
+
+=head3 LOG_OUTPUT and NOLOG_OUTPUT
+
+These tags override the value of the I<log_output> option on a
+per-command basis. For more information, see the description of
+I<log_output> in the L<"SUDOERS OPTIONS"> section below.
+
+=head2 Wildcards
+
+B<sudo> allows shell-style I<wildcards> (aka meta or glob characters)
+to be used in host names, path names and command line arguments in
+the I<sudoers> file. Wildcard matching is done via the B<POSIX>
+L<glob(3)> and L<fnmatch(3)> routines. Note that these are I<not>
+regular expressions.
+
+=over 8
+
+=item C<*>
+
+Matches any set of zero or more characters.
+
+=item C<?>
+
+Matches any single character.
+
+=item C<[...]>
+
+Matches any character in the specified range.
+
+=item C<[!...]>
+
+Matches any character B<not> in the specified range.
+
+=item C<\x>
+
+For any character "x", evaluates to "x". This is used to
+escape special characters such as: "*", "?", "[", and "}".
+
+=back
+
+POSIX character classes may also be used if your system's L<glob(3)>
+and L<fnmatch(3)> functions support them. However, because the
+C<':'> character has special meaning in I<sudoers>, it must be
+escaped. For example:
+
+ /bin/ls [[\:alpha\:]]*
+
+Would match any file name beginning with a letter.
+
+Note that a forward slash ('/') will B<not> be matched by
+wildcards used in the path name. When matching the command
+line arguments, however, a slash B<does> get matched by
+wildcards. This is to make a path like:
+
+ /usr/bin/*
+
+match F</usr/bin/who> but not F</usr/bin/X11/xterm>.
+
+=head2 Exceptions to wildcard rules
+
+The following exceptions apply to the above rules:
+
+=over 8
+
+=item C<"">
+
+If the empty string C<""> is the only command line argument in the
+I<sudoers> entry it means that command is not allowed to be run
+with B<any> arguments.
+
+=back
+
+=head2 Including other files from within sudoers
+
+It is possible to include other I<sudoers> files from within the
+I<sudoers> file currently being parsed using the C<#include> and
+C<#includedir> directives.
+
+This can be used, for example, to keep a site-wide I<sudoers> file
+in addition to a local, per-machine file. For the sake of this
+example the site-wide I<sudoers> will be F</etc/sudoers> and the
+per-machine one will be F</etc/sudoers.local>. To include
+F</etc/sudoers.local> from within F</etc/sudoers> we would use the
+following line in F</etc/sudoers>:
+
+=over 4
+
+C<#include /etc/sudoers.local>
+
+=back
+
+When B<sudo> reaches this line it will suspend processing of the
+current file (F</etc/sudoers>) and switch to F</etc/sudoers.local>.
+Upon reaching the end of F</etc/sudoers.local>, the rest of
+F</etc/sudoers> will be processed. Files that are included may
+themselves include other files. A hard limit of 128 nested include
+files is enforced to prevent include file loops.
+
+The file name may include the C<%h> escape, signifying the short form
+of the host name. I.e., if the machine's host name is "xerxes", then
+
+C<#include /etc/sudoers.%h>
+
+will cause B<sudo> to include the file F</etc/sudoers.xerxes>.
+
+The C<#includedir> directive can be used to create a F<sudo.d>
+directory that the system package manager can drop I<sudoers> rules
+into as part of package installation. For example, given:
+
+C<#includedir /etc/sudoers.d>
+
+B<sudo> will read each file in F</etc/sudoers.d>, skipping file
+names that end in C<~> or contain a C<.> character to avoid causing
+problems with package manager or editor temporary/backup files.
+Files are parsed in sorted lexical order. That is,
+F</etc/sudoers.d/01_first> will be parsed before
+F</etc/sudoers.d/10_second>. Be aware that because the sorting is
+lexical, not numeric, F</etc/sudoers.d/1_whoops> would be loaded
+B<after> F</etc/sudoers.d/10_second>. Using a consistent number
+of leading zeroes in the file names can be used to avoid such
+problems.
+
+Note that unlike files included via C<#include>, B<visudo> will not
+edit the files in a C<#includedir> directory unless one of them
+contains a syntax error. It is still possible to run B<visudo>
+with the C<-f> flag to edit the files directly.
+
+=head2 Other special characters and reserved words
+
+The pound sign ('#') is used to indicate a comment (unless it is
+part of a #include directive or unless it occurs in the context of
+a user name and is followed by one or more digits, in which case
+it is treated as a uid). Both the comment character and any text
+after it, up to the end of the line, are ignored.
+
+The reserved word B<ALL> is a built-in I<alias> that always causes
+a match to succeed. It can be used wherever one might otherwise
+use a C<Cmnd_Alias>, C<User_Alias>, C<Runas_Alias>, or C<Host_Alias>.
+You should not try to define your own I<alias> called B<ALL> as the
+built-in alias will be used in preference to your own. Please note
+that using B<ALL> can be dangerous since in a command context, it
+allows the user to run B<any> command on the system.
+
+An exclamation point ('!') can be used as a logical I<not> operator
+both in an I<alias> and in front of a C<Cmnd>. This allows one to
+exclude certain values. Note, however, that using a C<!> in
+conjunction with the built-in C<ALL> alias to allow a user to
+run "all but a few" commands rarely works as intended (see SECURITY
+NOTES below).
+
+Long lines can be continued with a backslash ('\') as the last
+character on the line.
+
+Whitespace between elements in a list as well as special syntactic
+characters in a I<User Specification> ('=', ':', '(', ')') is optional.
+
+The following characters must be escaped with a backslash ('\') when
+used as part of a word (e.g.E<nbsp>a user name or host name):
+'@', '!', '=', ':', ',', '(', ')', '\'.
+
+=head1 SUDOERS OPTIONS
+
+B<sudo>'s behavior can be modified by C<Default_Entry> lines, as
+explained earlier. A list of all supported Defaults parameters,
+grouped by type, are listed below.
+
+B<Boolean Flags>:
-If set, a user will receive a short lecture the first time he/she
-runs B<sudo>. This flag is I<@lecture@> by default.
+=over 16
+
+=item always_set_home
+
+If enabled, B<sudo> will set the C<HOME> environment variable to the
+home directory of the target user (which is root unless the B<-u>
+option is used). This effectively means that the B<-H> option is
+always implied. Note that C<HOME> is already set when the the
+I<env_reset> option is enabled, so I<always_set_home> is only
+effective for configurations where I<env_reset> is disabled.
+This flag is I<off> by default.
=item authenticate
may be overridden via the C<PASSWD> and C<NOPASSWD> tags.
This flag is I<on> by default.
-=item root_sudo
+=item closefrom_override
-If set, root is allowed to run B<sudo> too. Disabling this prevents users
-from "chaining" B<sudo> commands to get a root shell by doing something
-like C<"sudo sudo /bin/sh">.
+If set, the user may use B<sudo>'s B<-C> option which
+overrides the default starting point at which B<sudo> begins
+closing open file descriptors. This flag is I<off> by default.
+
+=item compress_io
+
+If set, and B<sudo> is configured to log a command's input or output,
+the I/O logs will be compressed using B<zlib>. This flag is I<on>
+by default when B<sudo> is compiled with B<zlib> support.
+
+=item env_editor
+
+If set, B<visudo> will use the value of the EDITOR or VISUAL
+environment variables before falling back on the default editor list.
+Note that this may create a security hole as it allows the user to
+run any arbitrary command as root without logging. A safer alternative
+is to place a colon-separated list of editors in the C<editor>
+variable. B<visudo> will then only use the EDITOR or VISUAL if
+they match a value specified in C<editor>. This flag is I<@env_editor@> by
+default.
+
+=item env_reset
+
+If set, B<sudo> will reset the environment to only contain the
+LOGNAME, MAIL, SHELL, USER, USERNAME and the C<SUDO_*> variables. Any
+variables in the caller's environment that match the C<env_keep>
+and C<env_check> lists are then added. The default contents of the
+C<env_keep> and C<env_check> lists are displayed when B<sudo> is
+run by root with the I<-V> option. If the I<secure_path> option
+is set, its value will be used for the C<PATH> environment variable.
This flag is I<on> by default.
+=item fast_glob
+
+Normally, B<sudo> uses the L<glob(3)> function to do shell-style
+globbing when matching path names. However, since it accesses the
+file system, L<glob(3)> can take a long time to complete for some
+patterns, especially when the pattern references a network file
+system that is mounted on demand (automounted). The I<fast_glob>
+option causes B<sudo> to use the L<fnmatch(3)> function, which does
+not access the file system to do its matching. The disadvantage
+of I<fast_glob> is that it is unable to match relative path names
+such as F<./ls> or F<../bin/ls>. This has security implications
+when path names that include globbing characters are used with the
+negation operator, C<'!'>, as such rules can be trivially bypassed.
+As such, this option should not be used when I<sudoers> contains rules
+that contain negated path names which include globbing characters.
+This flag is I<off> by default.
+
+=item fqdn
+
+Set this flag if you want to put fully qualified host names in the
+I<sudoers> file. I.e., instead of myhost you would use myhost.mydomain.edu.
+You may still use the short form if you wish (and even mix the two).
+Beware that turning on I<fqdn> requires B<sudo> to make DNS lookups
+which may make B<sudo> unusable if DNS stops working (for example
+if the machine is not plugged into the network). Also note that
+you must use the host's official name as DNS knows it. That is,
+you may not use a host alias (C<CNAME> entry) due to performance
+issues and the fact that there is no way to get all aliases from
+DNS. If your machine's host name (as returned by the C<hostname>
+command) is already fully qualified you shouldn't need to set
+I<fqdn>. This flag is I<@fqdn@> by default.
+
+=item ignore_dot
+
+If set, B<sudo> will ignore '.' or '' (current dir) in the C<PATH>
+environment variable; the C<PATH> itself is not modified. This
+flag is I<@ignore_dot@> by default.
+
+=item ignore_local_sudoers
+
+If set via LDAP, parsing of F<@sysconfdir@/sudoers> will be skipped.
+This is intended for Enterprises that wish to prevent the usage of local
+sudoers files so that only LDAP is used. This thwarts the efforts of
+rogue operators who would attempt to add roles to F<@sysconfdir@/sudoers>.
+When this option is present, F<@sysconfdir@/sudoers> does not even need to
+exist. Since this option tells B<sudo> how to behave when no specific LDAP
+entries have been matched, this sudoOption is only meaningful for the
+C<cn=defaults> section. This flag is I<off> by default.
+
+=item insults
+
+If set, B<sudo> will insult users when they enter an incorrect
+password. This flag is I<@insults@> by default.
+
=item log_host
-If set, the hostname will be logged in the (non-syslog) B<sudo> log file.
+If set, the host name will be logged in the (non-syslog) B<sudo> log file.
This flag is I<off> by default.
=item log_year
If set, the four-digit year will be logged in the (non-syslog) B<sudo> log file.
This flag is I<off> by default.
-=item shell_noargs
+=item long_otp_prompt
-If set and B<sudo> is invoked with no arguments it acts as if the
-B<-s> flag had been given. That is, it runs a shell as root (the
-shell is determined by the C<SHELL> environment variable if it is
-set, falling back on the shell listed in the invoking user's
-/etc/passwd entry if not). This flag is I<off> by default.
+When validating with a One Time Password (OPT) scheme such as
+B<S/Key> or B<OPIE>, a two-line prompt is used to make it easier
+to cut and paste the challenge to a local window. It's not as
+pretty as the default but some people find it more convenient. This
+flag is I<@long_otp_prompt@> by default.
-=item set_home
+=item mail_always
-If set and B<sudo> is invoked with the B<-s> flag the C<HOME>
-environment variable will be set to the home directory of the target
-user (which is root unless the B<-u> option is used). This effectively
-makes the B<-s> flag imply B<-H>. This flag is I<off> by default.
+Send mail to the I<mailto> user every time a users runs B<sudo>.
+This flag is I<off> by default.
-=item always_set_home
+=item mail_badpass
-If set, B<sudo> will set the C<HOME> environment variable to the home
-directory of the target user (which is root unless the B<-u> option is used).
-This effectively means that the B<-H> flag is always implied.
-This flag is I<off> by default.
+Send mail to the I<mailto> user if the user running B<sudo> does not
+enter the correct password. This flag is I<off> by default.
+
+=item mail_no_host
+
+If set, mail will be sent to the I<mailto> user if the invoking
+user exists in the I<sudoers> file, but is not allowed to run
+commands on the current host. This flag is I<@mail_no_host@> by default.
+
+=item mail_no_perms
+
+If set, mail will be sent to the I<mailto> user if the invoking
+user is allowed to use B<sudo> but the command they are trying is not
+listed in their I<sudoers> file entry or is explicitly denied.
+This flag is I<@mail_no_perms@> by default.
+
+=item mail_no_user
+
+If set, mail will be sent to the I<mailto> user if the invoking
+user is not in the I<sudoers> file. This flag is I<@mail_no_user@>
+by default.
+
+=item noexec
+
+If set, all commands run via B<sudo> will behave as if the C<NOEXEC>
+tag has been set, unless overridden by a C<EXEC> tag. See the
+description of I<NOEXEC and EXEC> below as well as the L<PREVENTING SHELL
+ESCAPES> section at the end of this manual. This flag is I<off> by default.
=item path_info
location of executables that the normal user does not have access
to. The disadvantage is that if the executable is simply not in
the user's C<PATH>, B<sudo> will tell the user that they are not
-allowed to run it, which can be confusing. This flag is I<off> by
-default.
+allowed to run it, which can be confusing. This flag is I<@path_info@>
+by default.
+
+=item passprompt_override
+
+The password prompt specified by I<passprompt> will normally only
+be used if the password prompt provided by systems such as PAM matches
+the string "Password:". If I<passprompt_override> is set, I<passprompt>
+will always be used. This flag is I<off> by default.
=item preserve_groups
-By default B<sudo> will initialize the group vector to the list of
+By default, B<sudo> will initialize the group vector to the list of
groups the target user is in. When I<preserve_groups> is set, the
user's existing group vector is left unaltered. The real and
effective group IDs, however, are still set to match the target
user. This flag is I<off> by default.
-=item fqdn
+=item pwfeedback
-Set this flag if you want to put fully qualified hostnames in the
-I<sudoers> file. I.e.: instead of myhost you would use myhost.mydomain.edu.
-You may still use the short form if you wish (and even mix the two).
-Beware that turning on I<fqdn> requires B<sudo> to make DNS lookups
-which may make B<sudo> unusable if DNS stops working (for example
-if the machine is not plugged into the network). Also note that
-you must use the host's official name as DNS knows it. That is,
-you may not use a host alias (C<CNAME> entry) due to performance
-issues and the fact that there is no way to get all aliases from
-DNS. If your machine's hostname (as returned by the C<hostname>
-command) is already fully qualified you shouldn't need to set
-I<fqdn>. This flag is I<@fqdn@> by default.
-
-=item insults
-
-If set, B<sudo> will insult users when they enter an incorrect
-password. This flag is I<@insults@> by default.
+By default, B<sudo> reads the password like most other Unix programs,
+by turning off echo until the user hits the return (or enter) key.
+Some users become confused by this as it appears to them that B<sudo>
+has hung at this point. When I<pwfeedback> is set, B<sudo> will
+provide visual feedback when the user presses a key. Note that
+this does have a security impact as an onlooker may be able to
+determine the length of the password being entered.
+This flag is I<off> by default.
=item requiretty
If set, B<sudo> will only run when the user is logged in to a real
-tty. This will disallow things like C<"rsh somehost sudo ls"> since
-rsh(1) does not allocate a tty. Because it is not possible to turn
-of echo when there is no tty present, some sites may with to set
-this flag to prevent a user from entering a visible password. This
-flag is I<off> by default.
+tty. When this flag is set, B<sudo> can only be run from a login
+session and not via other means such as L<cron(8)> or cgi-bin scripts.
+This flag is I<off> by default.
-=item env_editor
+=item root_sudo
-If set, B<visudo> will use the value of the EDITOR or VISUAL
-environment variables before falling back on the default editor list.
-Note that this may create a security hole as it allows the user to
-run any arbitrary command as root without logging. A safer alternative
-is to place a colon-separated list of editors in the C<editor>
-variable. B<visudo> will then only use the EDITOR or VISUAL if
-they match a value specified in C<editor>. This flag is C<@env_editor@> by
-default.
+If set, root is allowed to run B<sudo> too. Disabling this prevents users
+from "chaining" B<sudo> commands to get a root shell by doing something
+like C<"sudo sudo /bin/sh">. Note, however, that turning off I<root_sudo>
+will also prevent root from running B<sudoedit>.
+Disabling I<root_sudo> provides no real additional security; it
+exists purely for historical reasons.
+This flag is I<@root_sudo@> by default.
=item rootpw
=item runaspw
If set, B<sudo> will prompt for the password of the user defined by the
-I<runas_default> option (defaults to C<root>) instead of the password
-of the invoking user. This flag is I<off> by default.
+I<runas_default> option (defaults to C<@runas_default@>) instead of the
+password of the invoking user. This flag is I<off> by default.
-=item targetpw
+=item set_home
-If set, B<sudo> will prompt for the password of the user specified by
-the B<-u> flag (defaults to C<root>) instead of the password of the
-invoking user. This flag is I<off> by default.
+If enabled and B<sudo> is invoked with the B<-s> option the C<HOME>
+environment variable will be set to the home directory of the target
+user (which is root unless the B<-u> option is used). This effectively
+makes the B<-s> option imply B<-H>. Note that C<HOME> is already
+set when the the I<env_reset> option is enabled, so I<set_home> is
+only effective for configurations where I<env_reset> is disabled.
+This flag is I<off> by default.
=item set_logname
-Normally, B<sudo> will set the C<LOGNAME> and C<USER> environment variables
-to the name of the target user (usually root unless the B<-u> flag is given).
-However, since some programs (including the RCS revision control system)
-use C<LOGNAME> to determine the real identity of the user, it may be desirable
-to change this behavior. This can be done by negating the set_logname option.
+Normally, B<sudo> will set the C<LOGNAME>, C<USER> and C<USERNAME>
+environment variables to the name of the target user (usually root
+unless the B<-u> option is given). However, since some programs
+(including the RCS revision control system) use C<LOGNAME> to
+determine the real identity of the user, it may be desirable to
+change this behavior. This can be done by negating the set_logname
+option. Note that if the I<env_reset> option has not been disabled,
+entries in the I<env_keep> list will override the value of
+I<set_logname>. This flag is I<on> by default.
+
+=item setenv
+
+Allow the user to disable the I<env_reset> option from the command
+line. Additionally, environment variables set via the command line
+are not subject to the restrictions imposed by I<env_check>,
+I<env_delete>, or I<env_keep>. As such, only trusted users should
+be allowed to set variables in this manner. This flag is I<off>
+by default.
+
+=item shell_noargs
+
+If set and B<sudo> is invoked with no arguments it acts as if the
+B<-s> option had been given. That is, it runs a shell as root (the
+shell is determined by the C<SHELL> environment variable if it is
+set, falling back on the shell listed in the invoking user's
+/etc/passwd entry if not). This flag is I<off> by default.
=item stay_setuid
changes that behavior such that the real UID is left as the invoking
user's UID. In other words, this makes B<sudo> act as a setuid
wrapper. This can be useful on systems that disable some potentially
-dangerous functionality when a program is run setuid. Note, however,
-that this means that sudo will run with the real uid of the invoking
-user which may allow that user to kill B<sudo> before it can log a
-failure, depending on how your OS defines the interaction between
-signals and setuid processes.
+dangerous functionality when a program is run setuid. This option
+is only effective on systems with either the setreuid() or setresuid()
+function. This flag is I<off> by default.
-=item env_reset
+=item targetpw
-If set, B<sudo> will reset the environment to only contain the
-following variables: C<HOME>, C<LOGNAME>, C<PATH>, C<SHELL>, C<TERM>,
-C<DISPLAY>, C<XAUTHORITY>, C<XAUTHORIZATION>,
-C<LANG>, C<LANGUAGE>, C<LC_*>,
-and C<USER> (in addition to the C<SUDO_*> variables).
-
-Of these, only C<TERM>, C<DISPLAY>, C<XAUTHORITY>, C<XAUTHORIZATION>,
-C<LANG>, C<LANGUAGE>, and C<LC_*> are copied unaltered from the old environment.
-The other variables are set to default values (possibly modified
-by the value of the I<set_logname> option). If B<sudo> was compiled
-with the C<SECURE_PATH> option, its value will be used for the C<PATH>
-environment variable.
+If set, B<sudo> will prompt for the password of the user specified
+by the B<-u> option (defaults to C<root>) instead of the password
+of the invoking user. In addition, the timestamp file name will
+include the target user's name. Note that this flag precludes the
+use of a uid not listed in the passwd database as an argument to
+the B<-u> option. This flag is I<off> by default.
+
+=item log_input
+
+If set, B<sudo> will run the command in a I<pseudo tty> and log all
+user input.
+If the standard input is not connected to the user's tty, due to
+I/O redirection or because the command is part of a pipeline, that
+input is also captured and stored in a separate log file.
+
+Input is logged to the F</var/log/sudo-io> directory using a unique
+session ID that is included in the normal B<sudo> log line, prefixed
+with I<TSID=>.
+
+=item log_output
+
+If set, B<sudo> will run the command in a I<pseudo tty> and log all
+output that is sent to the screen, similar to the script(1) command.
+If the standard output or standard error is not connected to the
+user's tty, due to I/O redirection or because the command is part
+of a pipeline, that output is also captured and stored in separate
+log files.
+
+Output is logged to the
+F</var/log/sudo-io> directory using a unique session ID that is
+included in the normal B<sudo> log line, prefixed with I<TSID=>.
+
+Output logs may be viewed with the L<sudoreplay(8)> utility, which
+can also be used to list or search the available logs.
+
+=item tty_tickets
+
+If set, users must authenticate on a per-tty basis. With this flag
+enabled, B<sudo> will use a file named for the tty the user is
+logged in on in the user's time stamp directory. If disabled, the
+time stamp of the directory is used instead. This flag is
+I<@tty_tickets@> by default.
-This option is enabled by default.
+=item umask_override
-Other variables may be preserved with the I<env_keep> option.
+If set, B<sudo> will set the umask as specified by I<sudoers> without
+modification. This makes it possible to specify a more permissive
+umask in I<sudoers> than the user's own umask and matches historical
+behavior. If I<umask_override> is not set, B<sudo> will set the
+umask to be the union of the user's umask and what is specified in
+I<sudoers>. This flag is I<off> by default.
=item use_loginclass
login class if one exists. Only available if B<sudo> is configured with
the --with-logincap option. This flag is I<off> by default.
+=item use_pty
+
+If set, B<sudo> will run the command in a pseudo-pty even if no I/O
+logging is being gone. A malicious program run under B<sudo> could
+conceivably fork a background process that retains to the user's
+terminal device after the main program has finished executing. Use
+of this option will make that impossible.
+
+=item visiblepw
+
+By default, B<sudo> will refuse to run if the user must enter a
+password but it is not possible to disable echo on the terminal.
+If the I<visiblepw> flag is set, B<sudo> will prompt for a password
+even when it would be visible on the screen. This makes it possible
+to run things like C<"rsh somehost sudo ls"> since L<rsh(1)> does
+not allocate a tty. This flag is I<off> by default.
+
=back
B<Integers>:
-=over 12
+=over 16
+
+=item closefrom
+
+Before it executes a command, B<sudo> will close all open file
+descriptors other than standard input, standard output and standard
+error (ie: file descriptors 0-2). The I<closefrom> option can be used
+to specify a different file descriptor at which to start closing.
+The default is C<3>.
=item passwd_tries
B<Integers that can be used in a boolean context>:
-=over 12
+=over 16
=item loglinelen
effect on the syslog log file, only the file log. The default is
C<@loglen@> (use 0 or negate the option to disable word wrap).
+=item passwd_timeout
+
+Number of minutes before the B<sudo> password prompt times out, or
+C<0> for no timeout. The timeout may include a fractional component
+if minute granularity is insufficient, for example C<2.5>. The
+default is C<@password_timeout@>.
+
=item timestamp_timeout
Number of minutes that can elapse before B<sudo> will ask for a
-passwd again. The default is C<@timeout@>. Set this to C<0> to always
-prompt for a password.
+passwd again. The timeout may include a fractional component if
+minute granularity is insufficient, for example C<2.5>. The default
+is C<@timeout@>. Set this to C<0> to always prompt for a password.
If set to a value less than C<0> the user's timestamp will never
expire. This can be used to allow users to create or delete their
own timestamps via C<sudo -v> and C<sudo -k> respectively.
-=item passwd_timeout
+=item umask
-Number of minutes before the B<sudo> password prompt times out.
-The default is C<@password_timeout@>, set this to C<0> for no password timeout.
+Umask to use when running the command. Negate this option or set
+it to 0777 to preserve the user's umask. The actual umask that is
+used will be the union of the user's umask and the value of the
+I<umask> option, which defaults to C<@sudo_umask@>. This guarantees
+that B<sudo> never lowers the umask when running a command. Note
+on systems that use PAM, the default PAM configuration may specify
+its own umask which will override the value set in I<sudoers>.
-=item umask
+=back
+
+B<Strings>:
+
+=over 16
+
+=item badpass_message
+
+Message that is displayed if a user enters an incorrect password.
+The default is C<@badpass_message@> unless insults are enabled.
+
+=item editor
+
+A colon (':') separated list of editors allowed to be used with
+B<visudo>. B<visudo> will choose the editor that matches the user's
+EDITOR environment variable if possible, or the first editor in the
+list that exists and is executable. The default is C<"@editor@">.
+
+=item mailsub
+
+Subject of the mail sent to the I<mailto> user. The escape C<%h>
+will expand to the host name of the machine.
+Default is C<@mailsub@>.
+
+=item noexec_file
+
+Path to a shared library containing dummy versions of the execv(),
+execve() and fexecve() library functions that just return an error.
+This is used to implement the I<noexec> functionality on systems that
+support C<LD_PRELOAD> or its equivalent. Defaults to F<@noexec_file@>.
+
+=item passprompt
+
+The default prompt to use when asking for a password; can be overridden
+via the B<-p> option or the C<SUDO_PROMPT> environment variable.
+The following percent (`C<%>') escapes are supported:
+
+=over 4
+
+=item C<%H>
+
+expanded to the local host name including the domain name
+(on if the machine's host name is fully qualified or the I<fqdn>
+option is set)
+
+=item C<%h>
+
+expanded to the local host name without the domain name
-Umask to use when running the command. Negate this option or set
-it to 0777 to preserve the user's umask. The default is C<@sudo_umask@>.
+=item C<%p>
-=back
+expanded to the user whose password is being asked for (respects the
+I<rootpw>, I<targetpw> and I<runaspw> flags in I<sudoers>)
-B<Strings>:
+=item C<%U>
-=over 12
+expanded to the login name of the user the command will
+be run as (defaults to root)
-=item mailsub
+=item C<%u>
-Subject of the mail sent to the I<mailto> user. The escape C<%h>
-will expand to the hostname of the machine.
-Default is C<@mailsub@>.
+expanded to the invoking user's login name
-=item badpass_message
+=item C<%%>
-Message that is displayed if a user enters an incorrect password.
-The default is C<@badpass_message@> unless insults are enabled.
+two consecutive C<%> characters are collapsed into a single C<%> character
-=item timestampdir
+=back
-The directory in which B<sudo> stores its timestamp files.
-The default is F<@timedir@>.
+The default value is C<@passprompt@>.
-=item passprompt
+=item role
-The default prompt to use when asking for a password; can be overridden
-via the B<-p> option or the C<SUDO_PROMPT> environment variable. Supports
-two escapes: "%u" expands to the user's login name and "%h" expands
-to the local hostname. The default value is C<@passprompt@>.
+The default SELinux role to use when constructing a new security
+context to run the command. The default role may be overridden on
+a per-command basis in I<sudoers> or via command line options.
+This option is only available whe B<sudo> is built with SELinux support.
=item runas_default
-The default user to run commands as if the B<-u> flag is not specified
+The default user to run commands as if the B<-u> option is not specified
on the command line. This defaults to C<@runas_default@>.
-
-=item syslog_goodpri
-
-Syslog priority to use when user authenticates successfully.
-Defaults to C<@goodpri@>.
+Note that if I<runas_default> is set it B<must> occur before
+any C<Runas_Alias> specifications.
=item syslog_badpri
Syslog priority to use when user authenticates unsuccessfully.
Defaults to C<@badpri@>.
-=item editor
+=item syslog_goodpri
-A colon (':') separated list of editors allowed to be used with
-B<visudo>. B<visudo> will choose the editor that matches the user's
-USER environment variable if possible, or the first editor in the
-list that exists and is executable. The default is the path to vi
-on your system.
+Syslog priority to use when user authenticates successfully.
+Defaults to C<@goodpri@>.
-=back
+=item sudoers_locale
-B<Strings that can be used in a boolean context>:
+Locale to use when parsing the sudoers file. Note that changing
+the locale may affect how sudoers is interpreted.
+Defaults to C<"C">.
-=over 12
+=item timestampdir
-=item logfile
+The directory in which B<sudo> stores its timestamp files.
+The default is F<@timedir@>.
-Path to the B<sudo> log file (not the syslog log file). Setting a path
-turns on logging to a file; negating this option turns it off.
+=item timestampowner
-=item syslog
+The owner of the timestamp directory and the timestamps stored therein.
+The default is C<root>.
-Syslog facility if syslog is being used for logging (negate to
-disable syslog logging). Defaults to C<@logfac@>.
+=item type
-=item mailerpath
+The default SELinux type to use when constructing a new security
+context to run the command. The default type may be overridden on
+a per-command basis in I<sudoers> or via command line options.
+This option is only available whe B<sudo> is built with SELinux support.
-Path to mail program used to send warning mail.
-Defaults to the path to sendmail found at configure time.
+=back
-=item mailerflags
+B<Strings that can be used in a boolean context>:
-Flags to use when invoking mailer. Defaults to B<-t>.
+=over 12
-=item mailto
+=item askpass
-Address to send warning and error mail to. The address should
-be enclosed in double quotes (C<">) to protect against sudo
-interpreting the C<@> sign. Defaults to C<@mailto@>.
+The I<askpass> option specifies the fully qualified path to a helper
+program used to read the user's password when no terminal is
+available. This may be the case when B<sudo> is executed from a
+graphical (as opposed to text-based) application. The program
+specified by I<askpass> should display the argument passed to it
+as the prompt and write the user's password to the standard output.
+The value of I<askpass> may be overridden by the C<SUDO_ASKPASS>
+environment variable.
-=item exempt_group
+=item env_file
-Users in this group are exempt from password and PATH requirements. This
-option is turned on for Debian.
+The I<env_file> options specifies the fully qualified path to a
+file containing variables to be set in the environment of the program
+being run. Entries in this file should either be of the form
+C<VARIABLE=value> or C<export VARIABLE=value>. The value may
+optionally be surrounded by single or double quotes. Variables in
+this file are subject to other B<sudo> environment settings such
+as I<env_keep> and I<env_check>.
-=item verifypw
+=item exempt_group
-This option controls when a password will be required when a user runs
-B<sudo> with the B<-v> flag. It has the following possible values:
+Users in this group are exempt from password and PATH requirements.
+This is not set by default.
-=over 8
+=item lecture
-=item all
+This option controls when a short lecture will be printed along with
+the password prompt. It has the following possible values:
-All the user's I<sudoers> entries for the current host must have
-the C<NOPASSWD> flag set to avoid entering a password.
+=over 8
-=item any
+=item always
-At least one of the user's I<sudoers> entries for the current host
-must have the C<NOPASSWD> flag set to avoid entering a password.
+Always lecture the user.
=item never
-The user need never enter a password to use the B<-v> flag.
+Never lecture the user.
-=item always
+=item once
-The user must always enter a password to use the B<-v> flag.
+Only lecture the user the first time they run B<sudo>.
=back
-The default value is `all'.
+If no value is specified, a value of I<once> is implied.
+Negating the option results in a value of I<never> being used.
+The default value is I<@lecture@>.
+
+=item lecture_file
+
+Path to a file containing an alternate B<sudo> lecture that will
+be used in place of the standard lecture if the named file exists.
+By default, B<sudo> uses a built-in lecture.
=item listpw
This option controls when a password will be required when a
-user runs B<sudo> with the B<-l>. It has the following possible values:
+user runs B<sudo> with the B<-l> option. It has the following possible values:
=over 8
All the user's I<sudoers> entries for the current host must have
the C<NOPASSWD> flag set to avoid entering a password.
+=item always
+
+The user must always enter a password to use the B<-l> option.
+
=item any
At least one of the user's I<sudoers> entries for the current host
=item never
-The user need never enter a password to use the B<-l> flag.
-
-=item always
-
-The user must always enter a password to use the B<-l> flag.
-
-=back
-
-The default value is `any'.
+The user need never enter a password to use the B<-l> option.
=back
-B<Lists that can be used in a boolean context>:
-
-=over 12
-
-=item env_check
-
-Environment variables to be removed from the user's environment if
-the variable's value contains C<%> or C</> characters. This can
-be used to guard against printf-style format vulnerabilties in
-poorly-written programs. The argument may be a double-quoted,
-space-separated list or a single value without double-quotes. The
-list can be replaced, added to, deleted from, or disabled by using
-the C<=>, C<+=>, C<-=>, and C<!> operators respectively. The default
-list of environment variable to check is printed when B<sudo> is
-run by root with the I<-V> option.
-
-=item env_delete
-
-Environment variables to be removed from the user's environment.
-The argument may be a double-quoted, space-separated list or a
-single value without double-quotes. The list can be replaced, added
-to, deleted from, or disabled by using the C<=>, C<+=>, C<-=>, and
-C<!> operators respectively. The default list of environment
-variable to remove is printed when B<sudo> is run by root with the
-I<-V> option.
-
-=item env_keep
-
-Environment variables to be preserved in the user's environment
-when the I<env_reset> option is in effect. This allows fine-grained
-control over the environment B<sudo>-spawned processes will receive.
-The argument may be a double-quoted, space-separated list or a
-single value without double-quotes. The list can be replaced, added
-to, deleted from, or disabled by using the C<=>, C<+=>, C<-=>, and
-C<!> operators respectively. This list has no default members.
-
-=back
+If no value is specified, a value of I<any> is implied.
+Negating the option results in a value of I<never> being used.
+The default value is I<any>.
-When logging via syslog(3), B<sudo> accepts the following values for the syslog
-facility (the value of the B<syslog> Parameter): B<authpriv> (if your OS
-supports it), B<auth>, B<daemon>, B<user>, B<local0>, B<local1>, B<local2>,
-B<local3>, B<local4>, B<local5>, B<local6>, and B<local7>. The following
-syslog priorities are supported: B<alert>, B<crit>, B<debug>, B<emerg>,
-B<err>, B<info>, B<notice>, and B<warning>.
+=item logfile
-=head2 User Specification
+Path to the B<sudo> log file (not the syslog log file). Setting a path
+turns on logging to a file; negating this option turns it off.
+By default, B<sudo> logs via syslog.
- User_Spec ::= User_list Host_List '=' Cmnd_Spec_List \
- (':' User_Spec)*
+=item mailerflags
- Cmnd_Spec_List ::= Cmnd_Spec |
- Cmnd_Spec ',' Cmnd_Spec_List
+Flags to use when invoking mailer. Defaults to B<-t>.
- Cmnd_Spec ::= Runas_Spec? ('NOPASSWD:' | 'PASSWD:')? Cmnd
+=item mailerpath
- Runas_Spec ::= '(' Runas_List ')'
+Path to mail program used to send warning mail.
+Defaults to the path to sendmail found at configure time.
-A B<user specification> determines which commands a user may run
-(and as what user) on specified hosts. By default, commands are
-run as B<root>, but this can be changed on a per-command basis.
+=item mailfrom
-Let's break that down into its constituent parts:
+Address to use for the "from" address when sending warning and error
+mail. The address should be enclosed in double quotes (C<">) to
+protect against B<sudo> interpreting the C<@> sign. Defaults to
+the name of the user running B<sudo>.
-=head2 Runas_Spec
+=item mailto
-A C<Runas_Spec> is simply a C<Runas_List> (as defined above)
-enclosed in a set of parentheses. If you do not specify a
-C<Runas_Spec> in the user specification, a default C<Runas_Spec>
-of B<root> will be used. A C<Runas_Spec> sets the default for
-commands that follow it. What this means is that for the entry:
+Address to send warning and error mail to. The address should
+be enclosed in double quotes (C<">) to protect against B<sudo>
+interpreting the C<@> sign. Defaults to C<@mailto@>.
- dgb boulder = (operator) /bin/ls, /bin/kill, /usr/bin/who
+=item secure_path
-The user B<dgb> may run F</bin/ls>, F</bin/kill>, and
-F</usr/bin/lprm> -- but only as B<operator>. E.g.,
+Path used for every command run from B<sudo>. If you don't trust the
+people running B<sudo> to have a sane C<PATH> environment variable you may
+want to use this. Another use is if you want to have the "root path"
+be separate from the "user path." Users in the group specified by the
+I<exempt_group> option are not affected by I<secure_path>.
+This option is @secure_path@ by default.
- sudo -u operator /bin/ls.
+=item syslog
-It is also possible to override a C<Runas_Spec> later on in an
-entry. If we modify the entry like so:
+Syslog facility if syslog is being used for logging (negate to
+disable syslog logging). Defaults to C<@logfac@>.
- dgb boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm
+=item verifypw
-Then user B<dgb> is now allowed to run F</bin/ls> as B<operator>,
-but F</bin/kill> and F</usr/bin/lprm> as B<root>.
+This option controls when a password will be required when a user runs
+B<sudo> with the B<-v> option. It has the following possible values:
-=head2 NOPASSWD and PASSWD
+=over 8
-By default, B<sudo> requires that a user authenticate him or herself
-before running a command. This behavior can be modified via the
-C<NOPASSWD> tag. Like a C<Runas_Spec>, the C<NOPASSWD> tag sets
-a default for the commands that follow it in the C<Cmnd_Spec_List>.
-Conversely, the C<PASSWD> tag can be used to reverse things.
-For example:
+=item all
- ray rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm
+All the user's I<sudoers> entries for the current host must have
+the C<NOPASSWD> flag set to avoid entering a password.
-would allow the user B<ray> to run F</bin/kill>, F</bin/ls>, and
-F</usr/bin/lprm> as root on the machine rushmore as B<root> without
-authenticating himself. If we only want B<ray> to be able to
-run F</bin/kill> without a password the entry would be:
+=item always
- ray rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm
+The user must always enter a password to use the B<-v> option.
-Note, however, that the C<PASSWD> tag has no effect on users who are
-in the group specified by the exempt_group option.
+=item any
-By default, if the C<NOPASSWD> tag is applied to any of the entries
-for a user on the current host, he or she will be able to run
-C<sudo -l> without a password. Additionally, a user may only run
-C<sudo -v> without a password if the C<NOPASSWD> tag is present
-for all a user's entries that pertain to the current host.
-This behavior may be overridden via the verifypw and listpw options.
+At least one of the user's I<sudoers> entries for the current host
+must have the C<NOPASSWD> flag set to avoid entering a password.
-=head2 Wildcards (aka meta characters):
+=item never
-B<sudo> allows shell-style I<wildcards> to be used in pathnames
-as well as command line arguments in the I<sudoers> file. Wildcard
-matching is done via the B<POSIX> C<fnmatch(3)> routine. Note that
-these are I<not> regular expressions.
+The user need never enter a password to use the B<-v> option.
-=over 8
+=back
-=item C<*>
+If no value is specified, a value of I<all> is implied.
+Negating the option results in a value of I<never> being used.
+The default value is I<all>.
-Matches any set of zero or more characters.
+=back
-=item C<?>
+B<Lists that can be used in a boolean context>:
-Matches any single character.
+=over 16
-=item C<[...]>
+=item env_check
-Matches any character in the specified range.
+Environment variables to be removed from the user's environment if
+the variable's value contains C<%> or C</> characters. This can
+be used to guard against printf-style format vulnerabilities in
+poorly-written programs. The argument may be a double-quoted,
+space-separated list or a single value without double-quotes. The
+list can be replaced, added to, deleted from, or disabled by using
+the C<=>, C<+=>, C<-=>, and C<!> operators respectively. Regardless
+of whether the C<env_reset> option is enabled or disabled, variables
+specified by C<env_check> will be preserved in the environment if
+they pass the aforementioned check. The default list of environment
+variables to check is displayed when B<sudo> is run by root with
+the I<-V> option.
-=item C<[!...]>
+=item env_delete
-Matches any character B<not> in the specified range.
+Environment variables to be removed from the user's environment
+when the I<env_reset> option is not in effect. The argument may
+be a double-quoted, space-separated list or a single value without
+double-quotes. The list can be replaced, added to, deleted from,
+or disabled by using the C<=>, C<+=>, C<-=>, and C<!> operators
+respectively. The default list of environment variables to remove
+is displayed when B<sudo> is run by root with the I<-V> option.
+Note that many operating systems will remove potentially dangerous
+variables from the environment of any setuid process (such as
+B<sudo>).
-=item C<\x>
+=item env_keep
-For any character "x", evaluates to "x". This is used to
-escape special characters such as: "*", "?", "[", and "}".
+Environment variables to be preserved in the user's environment
+when the I<env_reset> option is in effect. This allows fine-grained
+control over the environment B<sudo>-spawned processes will receive.
+The argument may be a double-quoted, space-separated list or a
+single value without double-quotes. The list can be replaced, added
+to, deleted from, or disabled by using the C<=>, C<+=>, C<-=>, and
+C<!> operators respectively. The default list of variables to keep
+is displayed when B<sudo> is run by root with the I<-V> option.
=back
-Note that a forward slash ('/') will B<not> be matched by
-wildcards used in the pathname. When matching the command
-line arguments, however, as slash B<does> get matched by
-wildcards. This is to make a path like:
-
- /usr/bin/*
-
-match C</usr/bin/who> but not C</usr/bin/X11/xterm>.
+When logging via L<syslog(3)>, B<sudo> accepts the following values
+for the syslog facility (the value of the B<syslog> Parameter):
+B<authpriv> (if your OS supports it), B<auth>, B<daemon>, B<user>,
+B<local0>, B<local1>, B<local2>, B<local3>, B<local4>, B<local5>,
+B<local6>, and B<local7>. The following syslog priorities are
+supported: B<alert>, B<crit>, B<debug>, B<emerg>, B<err>, B<info>,
+B<notice>, and B<warning>.
-=head2 Exceptions to wildcard rules:
-
-The following exceptions apply to the above rules:
-
-=over 8
+=head1 FILES
-=item C<"">
+=over 24
-If the empty string C<""> is the only command line argument in the
-I<sudoers> entry it means that command is not allowed to be run
-with B<any> arguments.
+=item F<@sysconfdir@/sudoers>
-=back
+List of who can run what
-=head2 Other special characters and reserved words:
+=item F</etc/group>
-The pound sign ('#') is used to indicate a comment (unless it
-occurs in the context of a user name and is followed by one or
-more digits, in which case it is treated as a uid). Both the
-comment character and any text after it, up to the end of the line,
-are ignored.
+Local groups file
-The reserved word B<ALL> is a built in I<alias> that always causes
-a match to succeed. It can be used wherever one might otherwise
-use a C<Cmnd_Alias>, C<User_Alias>, C<Runas_Alias>, or C<Host_Alias>.
-You should not try to define your own I<alias> called B<ALL> as the
-built in alias will be used in preference to your own. Please note
-that using B<ALL> can be dangerous since in a command context, it
-allows the user to run B<any> command on the system.
+=item F</etc/netgroup>
-An exclamation point ('!') can be used as a logical I<not> operator
-both in an I<alias> and in front of a C<Cmnd>. This allows one to
-exclude certain values. Note, however, that using a C<!> in
-conjunction with the built in C<ALL> alias to allow a user to
-run "all but a few" commands rarely works as intended (see SECURITY
-NOTES below).
+List of network groups
-Long lines can be continued with a backslash ('\') as the last
-character on the line.
+=item F</var/log/sudo-io>
-Whitespace between elements in a list as well as special syntactic
-characters in a I<User Specification> ('=', ':', '(', ')') is optional.
+I/O log files
-The following characters must be escaped with a backslash ('\') when
-used as part of a word (e.g. a username or hostname):
-'@', '!', '=', ':', ',', '(', ')', '\'.
+=back
=head1 EXAMPLES
Below are example I<sudoers> entries. Admittedly, some of
-these are a bit contrived. First, we define our I<aliases>:
+these are a bit contrived. First, we allow a few environment
+variables to pass and then define our I<aliases>:
+
+ # Run X applications through sudo; HOME is used to find the
+ # .Xauthority file. Note that other programs use HOME to find
+ # configuration files and this may lead to privilege escalation!
+ Defaults env_keep += "DISPLAY HOME"
# User alias specification
User_Alias FULLTIMERS = millert, mikef, dowdy
# Runas alias specification
Runas_Alias OP = root, operator
Runas_Alias DB = oracle, sybase
+ Runas_Alias ADMINGRP = adm, oper
# Host alias specification
Host_Alias SPARC = bigtime, eclipse, moet, anchor :\
Cmnd_Alias KILL = /usr/bin/kill
Cmnd_Alias PRINTING = /usr/sbin/lpc, /usr/bin/lprm
Cmnd_Alias SHUTDOWN = /usr/sbin/shutdown
- Cmnd_Alias HALT = /usr/sbin/halt, /usr/sbin/fasthalt
- Cmnd_Alias REBOOT = /usr/sbin/reboot, /usr/sbin/fastboot
+ Cmnd_Alias HALT = /usr/sbin/halt
+ Cmnd_Alias REBOOT = /usr/sbin/reboot
Cmnd_Alias SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh, \
/usr/local/bin/tcsh, /usr/bin/rsh, \
/usr/local/bin/zsh
Cmnd_Alias SU = /usr/bin/su
+ Cmnd_Alias PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less
Here we override some of the compiled in default values. We want
-B<sudo> to log via syslog(3) using the I<auth> facility in all cases.
-We don't want to subject the full time staff to the B<sudo> lecture,
-and user B<millert> need not give a password. In addition, on the
+B<sudo> to log via L<syslog(3)> using the I<auth> facility in all
+cases. We don't want to subject the full time staff to the B<sudo>
+lecture, user B<millert> need not give a password, and we don't
+want to reset the C<LOGNAME>, C<USER> or C<USERNAME> environment
+variables when running commands as root. Additionally, on the
machines in the I<SERVERS> C<Host_Alias>, we keep an additional
local log file and make sure we log the year in each log line since
-the log entries will be kept around for several years.
+the log entries will be kept around for several years. Lastly, we
+disable shell escapes for the commands in the PAGERS C<Cmnd_Alias>
+(F</usr/bin/more>, F</usr/bin/pg> and F</usr/bin/less>).
- # Override built in defaults
+ # Override built-in defaults
Defaults syslog=auth
+ Defaults>root !set_logname
Defaults:FULLTIMERS !lecture
Defaults:millert !authenticate
Defaults@SERVERS log_year, logfile=/var/log/sudo.log
+ Defaults!PAGERS noexec
The I<User specification> is the part that actually determines who may
run what.
The user B<lisa> may run any command on any host in the I<CUNETS> alias
(the class B network C<128.138.0.0>).
- operator ALL = DUMPS, KILL, PRINTING, SHUTDOWN, HALT, REBOOT,\
- /usr/oper/bin/
+ operator ALL = DUMPS, KILL, SHUTDOWN, HALT, REBOOT, PRINTING,\
+ sudoedit /etc/printcap, /usr/oper/bin/
The B<operator> user may run commands limited to simple maintenance.
Here, those are commands related to backups, killing processes, the
joe ALL = /usr/bin/su operator
-The user B<joe> may only su(1) to operator.
+The user B<joe> may only L<su(1)> to operator.
- pete HPPA = /usr/bin/passwd [A-z]*, !/usr/bin/passwd root
+ pete HPPA = /usr/bin/passwd [A-Za-z]*, !/usr/bin/passwd root
+
+ %opers ALL = (: ADMINGRP) /usr/sbin/
+
+Users in the B<opers> group may run commands in F</usr/sbin/> as themselves
+with any group in the I<ADMINGRP> C<Runas_Alias> (the B<adm> and B<oper>
+groups).
The user B<pete> is allowed to change anyone's password except for
-root on the I<HPPA> machines. Note that this assumes passwd(1)
-does not take multiple usernames on the command line.
+root on the I<HPPA> machines. Note that this assumes L<passwd(1)>
+does not take multiple user names on the command line.
bob SPARC = (OP) ALL : SGI = (OP) ALL
jim +biglab = ALL
The user B<jim> may run any command on machines in the I<biglab> netgroup.
-B<Sudo> knows that "biglab" is a netgroup due to the '+' prefix.
+B<sudo> knows that "biglab" is a netgroup due to the '+' prefix.
+secretaries ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser
john ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root*
On the I<ALPHA> machines, user B<john> may su to anyone except root
-but he is not allowed to give su(1) any flags.
+but he is not allowed to specify any options to the L<su(1)> command.
jen ALL, !SERVERS = ALL
jill SERVERS = /usr/bin/, !SU, !SHELLS
For any machine in the I<SERVERS> C<Host_Alias>, B<jill> may run
-any commands in the directory /usr/bin/ except for those commands
+any commands in the directory F</usr/bin/> except for those commands
belonging to the I<SU> and I<SHELLS> C<Cmnd_Aliases>.
steve CSNETS = (operator) /usr/local/op_commands/
On the host www, any user in the I<WEBMASTERS> C<User_Alias> (will,
wendy, and wim), may run any command as user www (which owns the
-web pages) or simply su(1) to www.
+web pages) or simply L<su(1)> to www.
ALL CDROM = NOPASSWD: /sbin/umount /CDROM,\
/sbin/mount -o nosuid\,nodev /dev/cd0a /CDROM
program. Therefore, these kind of restrictions should be considered
advisory at best (and reinforced by policy).
+Furthermore, if the I<fast_glob> option is in use, it is not possible
+to reliably negate commands where the path name includes globbing
+(aka wildcard) characters. This is because the C library's
+L<fnmatch(3)> function cannot resolve relative paths. While this
+is typically only an inconvenience for rules that grant privileges,
+it can result in a security issue for rules that subtract or revoke
+privileges.
+
+For example, given the following I<sudoers> entry:
+
+ john ALL = /usr/bin/passwd [a-zA-Z0-9]*, /usr/bin/chsh [a-zA-Z0-9]*,
+ /usr/bin/chfn [a-zA-Z0-9]*, !/usr/bin/* root
+
+User B<john> can still run C</usr/bin/passwd root> if I<fast_glob> is
+enabled by changing to F</usr/bin> and running C<./passwd root> instead.
+
+=head1 PREVENTING SHELL ESCAPES
+
+Once B<sudo> executes a program, that program is free to do whatever
+it pleases, including run other programs. This can be a security
+issue since it is not uncommon for a program to allow shell escapes,
+which lets a user bypass B<sudo>'s access control and logging.
+Common programs that permit shell escapes include shells (obviously),
+editors, paginators, mail and terminal programs.
+
+There are two basic approaches to this problem:
+
+=over 10
+
+=item restrict
+
+Avoid giving users access to commands that allow the user to run
+arbitrary commands. Many editors have a restricted mode where shell
+escapes are disabled, though B<sudoedit> is a better solution to
+running editors via B<sudo>. Due to the large number of programs that
+offer shell escapes, restricting users to the set of programs that
+do not is often unworkable.
+
+=item noexec
+
+Many systems that support shared libraries have the ability to
+override default library functions by pointing an environment
+variable (usually C<LD_PRELOAD>) to an alternate shared library.
+On such systems, B<sudo>'s I<noexec> functionality can be used to
+prevent a program run by B<sudo> from executing any other programs.
+Note, however, that this applies only to native dynamically-linked
+executables. Statically-linked executables and foreign executables
+running under binary emulation are not affected.
+
+To tell whether or not B<sudo> supports I<noexec>, you can run
+the following as root:
+
+ sudo -V | grep "dummy exec"
+
+If the resulting output contains a line that begins with:
+
+ File containing dummy exec functions:
+
+then B<sudo> may be able to replace the exec family of functions
+in the standard library with its own that simply return an error.
+Unfortunately, there is no foolproof way to know whether or not
+I<noexec> will work at compile-time. I<noexec> should work on
+SunOS, Solaris, *BSD, Linux, IRIX, Tru64 UNIX, MacOS X, and HP-UX
+11.x. It is known B<not> to work on AIX and UnixWare. I<noexec>
+is expected to work on most operating systems that support the
+C<LD_PRELOAD> environment variable. Check your operating system's
+manual pages for the dynamic linker (usually ld.so, ld.so.1, dyld,
+dld.sl, rld, or loader) to see if C<LD_PRELOAD> is supported.
+
+To enable I<noexec> for a command, use the C<NOEXEC> tag as documented
+in the User Specification section above. Here is that example again:
+
+ aaron shanty = NOEXEC: /usr/bin/more, /usr/bin/vi
+
+This allows user B<aaron> to run F</usr/bin/more> and F</usr/bin/vi>
+with I<noexec> enabled. This will prevent those two commands from
+executing other commands (such as a shell). If you are unsure
+whether or not your system is capable of supporting I<noexec> you
+can always just try it out and see if it works.
+
+=back
+
+Note that restricting shell escapes is not a panacea. Programs
+running as root are still capable of many potentially hazardous
+operations (such as changing or overwriting files) that could lead
+to unintended privilege escalation. In the specific case of an
+editor, a safer approach is to give the user permission to run
+B<sudoedit>.
+
+=head1 SEE ALSO
+
+L<rsh(1)>, L<su(1)>, L<fnmatch(3)>, L<glob(3)>, L<sudo(8)>, L<visudo(8)>
+
=head1 CAVEATS
The I<sudoers> file should B<always> be edited by the B<visudo>
will not run with a syntactically incorrect I<sudoers> file.
When using netgroups of machines (as opposed to users), if you
-store fully qualified hostnames in the netgroup (as is usually the
-case), you either need to have the machine's hostname be fully qualified
+store fully qualified host name in the netgroup (as is usually the
+case), you either need to have the machine's host name be fully qualified
as returned by the C<hostname> command or use the I<fqdn> option in
I<sudoers>.
-=head1 FILES
+=head1 BUGS
- @sysconfdir@/sudoers List of who can run what
- /etc/group Local groups file
- /etc/netgroup List of network groups
+If you feel you have found a bug in B<sudo>, please submit a bug report
+at http://www.sudo.ws/sudo/bugs/
-=head1 SEE ALSO
+=head1 SUPPORT
+
+Limited free support is available via the sudo-users mailing list,
+see http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or
+search the archives.
+
+=head1 DISCLAIMER
-rsh(1), sudo(8), visudo(8), su(1), fnmatch(3).
+B<sudo> is provided ``AS IS'' and any express or implied warranties,
+including, but not limited to, the implied warranties of merchantability
+and fitness for a particular purpose are disclaimed. See the LICENSE
+file distributed with B<sudo> or http://www.sudo.ws/sudo/license.html
+for complete details.
projects / debian / sudo / blobdiff