-.\" Automatically generated by Pod::Man version 1.15
-.\" Thu Apr 25 09:34:54 2002
+.\" Copyright (c) 1994-1996,1998-2004 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
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+.\" 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.
+.\"
+.\" 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.
+.\"
+.\" $Sudo: sudoers.pod,v 1.96 2004/09/06 20:45:27 millert Exp $
+.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14
.\"
.\" Standard preamble:
-.\" ======================================================================
+.\" ========================================================================
.de Sh \" Subsection heading
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..
-.de Ip \" List item
-.br
-.ie \\n(.$>=3 .ne \\$3
-.el .ne 3
-.IP "\\$1" \\$2
-..
.de Vb \" Begin verbatim text
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+.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to
+.\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C'
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-.\" If the F register is turned on, we'll generate index entries on stderr
-.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and
-.\" index entries marked with X<> in POD. Of course, you'll have to process
-.\" the output yourself in some meaningful fashion.
+.\" If the F register is turned on, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
+.\" entries marked with X<> in POD. Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
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+.\" For nroff, turn off justification. Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
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-.\" ======================================================================
+.\" ========================================================================
.\"
-.IX Title "sudoers @mansectform@"
-.TH sudoers @mansectform@ "1.6.6" "April 25, 2002" "MAINTENANCE COMMANDS"
-.UC
+.IX Title "SUDOERS @mansectform@"
+.TH SUDOERS @mansectform@ "November 28, 2004" "1.6.8p5" "MAINTENANCE COMMANDS"
.SH "NAME"
sudoers \- list of which users may execute what
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
-The \fIsudoers\fR file is composed of two types of entries:
-aliases (basically variables) and user specifications
-(which specify who may run what). The grammar of \fIsudoers\fR
-will be described below in Extended Backus-Naur Form (\s-1EBNF\s0).
-Don't despair if you don't know what \s-1EBNF\s0 is; it is fairly
-simple, and the definitions below are annotated.
+The \fIsudoers\fR file is composed of two types of entries: aliases
+(basically variables) and user specifications (which specify who
+may run what).
+.PP
+When multiple entries match for a user, they are applied in order.
+Where there are conflicting values, the last match is used (which
+is not necessarily the most specific match).
+.PP
+The \fIsudoers\fR grammar will be described below in Extended Backus-Naur
+Form (\s-1EBNF\s0). Don't despair if you don't know what \s-1EBNF\s0 is; it is
+fairly simple, and the definitions below are annotated.
.Sh "Quick guide to \s-1EBNF\s0"
.IX Subsection "Quick guide to EBNF"
\&\s-1EBNF\s0 is a concise and exact way of describing the grammar of a language.
.Vb 1
\& symbol ::= definition | alternate1 | alternate2 ...
.Ve
+.PP
Each \fIproduction rule\fR references others and thus makes up a
grammar for the language. \s-1EBNF\s0 also contains the following
operators, which many readers will recognize from regular
expressions. Do not, however, confuse them with \*(L"wildcard\*(R"
characters, which have different meanings.
-.Ip "\f(CW\*(C`?\*(C'\fR" 8
+.ie n .IP "\*(C`?\*(C'" 8
+.el .IP "\f(CW\*(C`?\*(C'\fR" 8
.IX Item "?"
Means that the preceding symbol (or group of symbols) is optional.
That is, it may appear once or not at all.
-.Ip "\f(CW\*(C`*\*(C'\fR" 8
+.ie n .IP "\*(C`*\*(C'" 8
+.el .IP "\f(CW\*(C`*\*(C'\fR" 8
.IX Item "*"
Means that the preceding symbol (or group of symbols) may appear
zero or more times.
-.Ip "\f(CW\*(C`+\*(C'\fR" 8
+.ie n .IP "\*(C`+\*(C'" 8
+.el .IP "\f(CW\*(C`+\*(C'\fR" 8
.IX Item "+"
Means that the preceding symbol (or group of symbols) may appear
one or more times.
\& 'Host_Alias' Host_Alias (':' Host_Alias)* |
\& 'Cmnd_Alias' Cmnd_Alias (':' Cmnd_Alias)*
.Ve
+.PP
.Vb 1
\& User_Alias ::= NAME '=' User_List
.Ve
+.PP
.Vb 1
\& Runas_Alias ::= NAME '=' Runas_List
.Ve
+.PP
.Vb 1
\& Host_Alias ::= NAME '=' Host_List
.Ve
+.PP
.Vb 1
\& Cmnd_Alias ::= NAME '=' Cmnd_List
.Ve
+.PP
.Vb 1
\& NAME ::= [A-Z]([A-Z][0-9]_)*
.Ve
+.PP
Each \fIalias\fR definition is of the form
.PP
.Vb 1
\& Alias_Type NAME = item1, item2, ...
.Ve
+.PP
where \fIAlias_Type\fR is one of \f(CW\*(C`User_Alias\*(C'\fR, \f(CW\*(C`Runas_Alias\*(C'\fR, \f(CW\*(C`Host_Alias\*(C'\fR,
or \f(CW\*(C`Cmnd_Alias\*(C'\fR. A \f(CW\*(C`NAME\*(C'\fR is a string of uppercase letters, numbers,
-and the underscore characters ('_'). A \f(CW\*(C`NAME\*(C'\fR \fBmust\fR start with an
+and underscore characters ('_'). A \f(CW\*(C`NAME\*(C'\fR \fBmust\fR 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.,
.PP
.Vb 1
\& Alias_Type NAME = item1, item2, item3 : NAME = item4, item5
.Ve
+.PP
The definitions of what constitutes a valid \fIalias\fR member follow.
.PP
.Vb 2
\& User_List ::= User |
\& User ',' User_List
.Ve
+.PP
.Vb 4
\& User ::= '!'* username |
\& '!'* '%'group |
\& '!'* '+'netgroup |
\& '!'* User_Alias
.Ve
-A \f(CW\*(C`User_List\*(C'\fR 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.
+.PP
+A \f(CW\*(C`User_List\*(C'\fR is made up of one or more usernames, 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.
.PP
.Vb 2
\& Runas_List ::= Runas_User |
\& Runas_User ',' Runas_List
.Ve
+.PP
.Vb 5
\& Runas_User ::= '!'* username |
\& '!'* '#'uid |
\& '!'* +netgroup |
\& '!'* Runas_Alias
.Ve
+.PP
A \f(CW\*(C`Runas_List\*(C'\fR is similar to a \f(CW\*(C`User_List\*(C'\fR except that it can
also contain uids (prefixed with '#') and instead of \f(CW\*(C`User_Alias\*(C'\fRes
-it can contain \f(CW\*(C`Runas_Alias\*(C'\fRes.
+it can contain \f(CW\*(C`Runas_Alias\*(C'\fRes. Note that usernames 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 usernames with the same uid (e.g. root and toor), you
+can use a uid instead (#0 in the example given).
.PP
.Vb 2
\& Host_List ::= Host |
\& Host ',' Host_List
.Ve
+.PP
.Vb 5
\& Host ::= '!'* hostname |
\& '!'* ip_addr |
\& '!'* '+'netgroup |
\& '!'* Host_Alias
.Ve
+.PP
A \f(CW\*(C`Host_List\*(C'\fR is made up of one or more hostnames, \s-1IP\s0 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 \fIinterface\fR\|(s) will be used when matching.
+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 \s-1CIDR\s0 notation (number of bits, e.g. 24). A hostname
-may include shell-style wildcards (see `Wildcards' section below),
+may include shell-style wildcards (see the Wildcards section below),
but unless the \f(CW\*(C`hostname\*(C'\fR command on your machine returns the fully
qualified hostname, you'll need to use the \fIfqdn\fR option for wildcards
to be useful.
\& Cmnd_List ::= Cmnd |
\& Cmnd ',' Cmnd_List
.Ve
+.PP
.Vb 3
\& commandname ::= filename |
\& filename args |
\& filename '""'
.Ve
-.Vb 3
+.PP
+.Vb 4
\& Cmnd ::= '!'* commandname |
\& '!'* directory |
+\& '!'* "sudoedit" |
\& '!'* Cmnd_Alias
.Ve
+.PP
A \f(CW\*(C`Cmnd_List\*(C'\fR 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
+shell-style wildcards (see the Wildcards section below). A simple
filename 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 \f(CW\*(C`""\*(C'\fR to indicate that the command
+wildcards). Alternately, you can specify \f(CW""\fR to indicate that the command
may only be run \fBwithout\fR command line arguments. A directory is a
fully qualified pathname ending in a '/'. When you specify a directory
in a \f(CW\*(C`Cmnd_List\*(C'\fR, the user will be able to run any file within that directory
in the \f(CW\*(C`Cmnd\*(C'\fR 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 '\e' if they are used in command
-arguments: ',', ':', '=', '\e'.
+arguments: ',', ':', '=', '\e'. The special command \f(CW"sudoedit"\fR
+is used to permit a user to run \fBsudo\fR with the \fB\-e\fR flag (or
+as \fBsudoedit\fR). It may take command line arguments just as
+a normal command does.
.Sh "Defaults"
.IX Subsection "Defaults"
Certain configuration options may be changed from their default
values at runtime via one or more \f(CW\*(C`Default_Entry\*(C'\fR 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.
+may affect all users on any host, all users on a specific host, a
+specific user, or commands being run as a specific user.
.PP
-.Vb 3
-\& Default_Type ::= 'Defaults' ||
-\& 'Defaults' ':' User ||
-\& 'Defaults' '@' Host
+.Vb 4
+\& Default_Type ::= 'Defaults' |
+\& 'Defaults' '@' Host |
+\& 'Defaults' ':' User |
+\& 'Defaults' '>' RunasUser
.Ve
+.PP
.Vb 1
\& Default_Entry ::= Default_Type Parameter_List
.Ve
+.PP
+.Vb 2
+\& Parameter_List ::= Parameter |
+\& Parameter ',' Parameter_List
+.Ve
+.PP
.Vb 4
-\& Parameter ::= Parameter '=' Value ||
-\& Parameter '+=' Value ||
-\& Parameter '-=' Value ||
-\& '!'* Parameter ||
+\& Parameter ::= Parameter '=' Value |
+\& Parameter '+=' Value |
+\& Parameter '-=' Value |
+\& '!'* Parameter
.Ve
+.PP
Parameters may be \fBflags\fR, \fBinteger\fR values, \fBstrings\fR, or \fBlists\fR.
Flags are implicitly boolean and can be turned off via the '!'
operator. Some integer, string and list parameters may also be
It is not an error to use the \f(CW\*(C`\-=\*(C'\fR operator to remove an element
that does not exist in a list.
.PP
-Note that since the \fIsudoers\fR 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.
-.PP
\&\fBFlags\fR:
-.Ip "long_otp_prompt" 12
+.IP "long_otp_prompt" 12
.IX Item "long_otp_prompt"
When validating with a One Time Password scheme (\fBS/Key\fR or \fB\s-1OPIE\s0\fR),
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 \fI@long_otp_prompt@\fR
by default.
-.Ip "ignore_dot" 12
+.IP "ignore_dot" 12
.IX Item "ignore_dot"
If set, \fBsudo\fR will ignore '.' or '' (current dir) in the \f(CW\*(C`PATH\*(C'\fR
environment variable; the \f(CW\*(C`PATH\*(C'\fR itself is not modified. This
-flag is \fI@ignore_dot@\fR by default.
-.Ip "mail_always" 12
+flag is \fI@ignore_dot@\fR by default. Currently, while it is possible
+to set \fIignore_dot\fR in \fIsudoers\fR, its value is not used. This option
+should be considered read-only (it will be fixed in a future version
+of \fBsudo\fR).
+.IP "mail_always" 12
.IX Item "mail_always"
Send mail to the \fImailto\fR user every time a users runs \fBsudo\fR.
This flag is \fIoff\fR by default.
-.Ip "mail_badpass" 12
+.IP "mail_badpass" 12
.IX Item "mail_badpass"
Send mail to the \fImailto\fR user if the user running sudo does not
enter the correct password. This flag is \fIoff\fR by default.
-.Ip "mail_no_user" 12
+.IP "mail_no_user" 12
.IX Item "mail_no_user"
If set, mail will be sent to the \fImailto\fR user if the invoking
user is not in the \fIsudoers\fR file. This flag is \fI@mail_no_user@\fR
by default.
-.Ip "mail_no_host" 12
+.IP "mail_no_host" 12
.IX Item "mail_no_host"
If set, mail will be sent to the \fImailto\fR user if the invoking
user exists in the \fIsudoers\fR file, but is not allowed to run
commands on the current host. This flag is \fI@mail_no_host@\fR by default.
-.Ip "mail_no_perms" 12
+.IP "mail_no_perms" 12
.IX Item "mail_no_perms"
If set, mail will be sent to the \fImailto\fR user if the invoking
-user allowed to use \fBsudo\fR but the command they are trying is not
-listed in their \fIsudoers\fR file entry. This flag is \fI@mail_no_perms@\fR
-by default.
-.Ip "tty_tickets" 12
+user is allowed to use \fBsudo\fR but the command they are trying is not
+listed in their \fIsudoers\fR file entry or is explicitly denied.
+This flag is \fI@mail_no_perms@\fR by default.
+.IP "tty_tickets" 12
.IX Item "tty_tickets"
If set, users must authenticate on a per-tty basis. Normally,
\&\fBsudo\fR uses a directory in the ticket dir with the same name as
the user running it. With this flag enabled, \fBsudo\fR will use a
file named for the tty the user is logged in on in that directory.
This flag is \fI@tty_tickets@\fR by default.
-.Ip "lecture" 12
-.IX Item "lecture"
-If set, a user will receive a short lecture the first time he/she
-runs \fBsudo\fR. This flag is \fI@lecture@\fR by default.
-.Ip "authenticate" 12
+.IP "authenticate" 12
.IX Item "authenticate"
If set, users must authenticate themselves via a password (or other
means of authentication) before they may run commands. This default
may be overridden via the \f(CW\*(C`PASSWD\*(C'\fR and \f(CW\*(C`NOPASSWD\*(C'\fR tags.
This flag is \fIon\fR by default.
-.Ip "root_sudo" 12
+.IP "root_sudo" 12
.IX Item "root_sudo"
If set, root is allowed to run \fBsudo\fR too. Disabling this prevents users
from \*(L"chaining\*(R" \fBsudo\fR commands to get a root shell by doing something
-like \f(CW\*(C`"sudo sudo /bin/sh"\*(C'\fR.
-This flag is \fIon\fR by default.
-.Ip "log_host" 12
+like \f(CW"sudo sudo /bin/sh"\fR. Note, however, that turning off \fIroot_sudo\fR
+will also prevent root and from running \fBsudoedit\fR.
+Disabling \fIroot_sudo\fR provides no real additional security; it
+exists purely for historical reasons.
+This flag is \fI@root_sudo@\fR by default.
+.IP "log_host" 12
.IX Item "log_host"
-If set, the hostname will be logged in the (non-syslog) \fBsudo\fR log file.
+If set, the hostname will be logged in the (non\-syslog) \fBsudo\fR log file.
This flag is \fIoff\fR by default.
-.Ip "log_year" 12
+.IP "log_year" 12
.IX Item "log_year"
-If set, the four-digit year will be logged in the (non-syslog) \fBsudo\fR log file.
+If set, the four-digit year will be logged in the (non\-syslog) \fBsudo\fR log file.
This flag is \fIoff\fR by default.
-.Ip "shell_noargs" 12
+.IP "shell_noargs" 12
.IX Item "shell_noargs"
If set and \fBsudo\fR is invoked with no arguments it acts as if the
\&\fB\-s\fR flag had been given. That is, it runs a shell as root (the
shell is determined by the \f(CW\*(C`SHELL\*(C'\fR 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 \fIoff\fR by default.
-.Ip "set_home" 12
+.IP "set_home" 12
.IX Item "set_home"
If set and \fBsudo\fR is invoked with the \fB\-s\fR flag the \f(CW\*(C`HOME\*(C'\fR
environment variable will be set to the home directory of the target
user (which is root unless the \fB\-u\fR option is used). This effectively
makes the \fB\-s\fR flag imply \fB\-H\fR. This flag is \fIoff\fR by default.
-.Ip "always_set_home" 12
+.IP "always_set_home" 12
.IX Item "always_set_home"
If set, \fBsudo\fR will set the \f(CW\*(C`HOME\*(C'\fR environment variable to the home
directory of the target user (which is root unless the \fB\-u\fR option is used).
This effectively means that the \fB\-H\fR flag is always implied.
This flag is \fIoff\fR by default.
-.Ip "path_info" 12
+.IP "path_info" 12
.IX Item "path_info"
Normally, \fBsudo\fR will tell the user when a command could not be
found in their \f(CW\*(C`PATH\*(C'\fR environment variable. Some sites may wish
the user's \f(CW\*(C`PATH\*(C'\fR, \fBsudo\fR will tell the user that they are not
allowed to run it, which can be confusing. This flag is \fIoff\fR by
default.
-.Ip "preserve_groups" 12
+.IP "preserve_groups" 12
.IX Item "preserve_groups"
By default \fBsudo\fR will initialize the group vector to the list of
groups the target user is in. When \fIpreserve_groups\fR 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 \fIoff\fR by default.
-.Ip "fqdn" 12
+.IP "fqdn" 12
.IX Item "fqdn"
Set this flag if you want to put fully qualified hostnames in the
-\&\fIsudoers\fR file. I.e.: instead of myhost you would use myhost.mydomain.edu.
+\&\fIsudoers\fR 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 \fIfqdn\fR requires \fBsudo\fR to make \s-1DNS\s0 lookups
which may make \fBsudo\fR unusable if \s-1DNS\s0 stops working (for example
\&\s-1DNS\s0. If your machine's hostname (as returned by the \f(CW\*(C`hostname\*(C'\fR
command) is already fully qualified you shouldn't need to set
\&\fIfqdn\fR. This flag is \fI@fqdn@\fR by default.
-.Ip "insults" 12
+.IP "insults" 12
.IX Item "insults"
If set, \fBsudo\fR will insult users when they enter an incorrect
password. This flag is \fI@insults@\fR by default.
-.Ip "requiretty" 12
+.IP "requiretty" 12
.IX Item "requiretty"
If set, \fBsudo\fR will only run when the user is logged in to a real
-tty. This will disallow things like \f(CW\*(C`"rsh somehost sudo ls"\*(C'\fR since
+tty. This will disallow things like \f(CW"rsh somehost sudo ls"\fR since
\&\fIrsh\fR\|(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
+off 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 \fIoff\fR by default.
-.Ip "env_editor" 12
+.IP "env_editor" 12
.IX Item "env_editor"
If set, \fBvisudo\fR will use the value of the \s-1EDITOR\s0 or \s-1VISUAL\s0
environment variables before falling back on the default editor list.
variable. \fBvisudo\fR will then only use the \s-1EDITOR\s0 or \s-1VISUAL\s0 if
they match a value specified in \f(CW\*(C`editor\*(C'\fR. This flag is \f(CW\*(C`@env_editor@\*(C'\fR by
default.
-.Ip "rootpw" 12
+.IP "rootpw" 12
.IX Item "rootpw"
If set, \fBsudo\fR will prompt for the root password instead of the password
of the invoking user. This flag is \fIoff\fR by default.
-.Ip "runaspw" 12
+.IP "runaspw" 12
.IX Item "runaspw"
If set, \fBsudo\fR will prompt for the password of the user defined by the
-\&\fIrunas_default\fR option (defaults to \f(CW\*(C`root\*(C'\fR) instead of the password
-of the invoking user. This flag is \fIoff\fR by default.
-.Ip "targetpw" 12
+\&\fIrunas_default\fR option (defaults to \f(CW\*(C`@runas_default@\*(C'\fR) instead of the
+password of the invoking user. This flag is \fIoff\fR by default.
+.IP "targetpw" 12
.IX Item "targetpw"
If set, \fBsudo\fR will prompt for the password of the user specified by
the \fB\-u\fR flag (defaults to \f(CW\*(C`root\*(C'\fR) instead of the password of the
-invoking user. This flag is \fIoff\fR by default.
-.Ip "set_logname" 12
+invoking user. Note that this precludes the use of a uid not listed
+in the passwd database as an argument to the \fB\-u\fR flag.
+This flag is \fIoff\fR by default.
+.IP "set_logname" 12
.IX Item "set_logname"
Normally, \fBsudo\fR will set the \f(CW\*(C`LOGNAME\*(C'\fR and \f(CW\*(C`USER\*(C'\fR environment variables
to the name of the target user (usually root unless the \fB\-u\fR flag is given).
However, since some programs (including the \s-1RCS\s0 revision control system)
use \f(CW\*(C`LOGNAME\*(C'\fR 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.
-.Ip "stay_setuid" 12
+.IP "stay_setuid" 12
.IX Item "stay_setuid"
Normally, when \fBsudo\fR executes a command the real and effective
UIDs are set to the target user (root by default). This option
user which may allow that user to kill \fBsudo\fR before it can log a
failure, depending on how your \s-1OS\s0 defines the interaction between
signals and setuid processes.
-.Ip "env_reset" 12
+.IP "env_reset" 12
.IX Item "env_reset"
If set, \fBsudo\fR will reset the environment to only contain the
following variables: \f(CW\*(C`HOME\*(C'\fR, \f(CW\*(C`LOGNAME\*(C'\fR, \f(CW\*(C`PATH\*(C'\fR, \f(CW\*(C`SHELL\*(C'\fR, \f(CW\*(C`TERM\*(C'\fR,
with the \f(CW\*(C`SECURE_PATH\*(C'\fR option, its value will be used for the \f(CW\*(C`PATH\*(C'\fR
environment variable.
Other variables may be preserved with the \fIenv_keep\fR option.
-.Ip "use_loginclass" 12
+.IP "use_loginclass" 12
.IX Item "use_loginclass"
If set, \fBsudo\fR will apply the defaults specified for the target user's
login class if one exists. Only available if \fBsudo\fR is configured with
-the \-\-with-logincap option. This flag is \fIoff\fR by default.
+the \-\-with\-logincap option. This flag is \fIoff\fR by default.
+.IP "noexec" 12
+.IX Item "noexec"
+If set, all commands run via sudo will behave as if the \f(CW\*(C`NOEXEC\*(C'\fR
+tag has been set, unless overridden by a \f(CW\*(C`EXEC\*(C'\fR tag. See the
+description of \fI\s-1NOEXEC\s0 and \s-1EXEC\s0\fR below as well as the \*(L"\s-1PREVENTING\s0 \s-1SHELL\s0 \s-1ESCAPES\s0\*(R" section at the end of this manual. This flag is \fIoff\fR by default.
+.IP "ignore_local_sudoers" 12
+.IX Item "ignore_local_sudoers"
+If set via \s-1LDAP\s0, parsing of \f(CW@sysconfdir\fR@/sudoers will be skipped.
+This is intended for an Enterprises that wish to prevent the usage of local
+sudoers files so that only \s-1LDAP\s0 is used. This thwarts the efforts of
+rogue operators who would attempt to add roles to \f(CW@sysconfdir\fR@/sudoers.
+When this option is present, \f(CW@sysconfdir\fR@/sudoers does not even need to exist.
+Since this options tells sudo how to behave when no specific \s-1LDAP\s0 entries
+have been matched, this sudoOption is only meaningful for the cn=defaults
+section. This flag is \fIoff\fR by default.
.PP
\&\fBIntegers\fR:
-.Ip "passwd_tries" 12
+.IP "passwd_tries" 12
.IX Item "passwd_tries"
The number of tries a user gets to enter his/her password before
\&\fBsudo\fR logs the failure and exits. The default is \f(CW\*(C`@passwd_tries@\*(C'\fR.
.PP
\&\fBIntegers that can be used in a boolean context\fR:
-.Ip "loglinelen" 12
+.IP "loglinelen" 12
.IX Item "loglinelen"
Number of characters per line for the file log. This value is used
to decide when to wrap lines for nicer log files. This has no
effect on the syslog log file, only the file log. The default is
\&\f(CW\*(C`@loglen@\*(C'\fR (use 0 or negate the option to disable word wrap).
-.Ip "timestamp_timeout" 12
+.IP "timestamp_timeout" 12
.IX Item "timestamp_timeout"
Number of minutes that can elapse before \fBsudo\fR will ask for a
-passwd again. The default is \f(CW\*(C`@timeout@\*(C'\fR. Set this to \f(CW\*(C`0\*(C'\fR to always
+passwd again. The default is \f(CW\*(C`@timeout@\*(C'\fR. Set this to \f(CW0\fR to always
prompt for a password.
-If set to a value less than \f(CW\*(C`0\*(C'\fR the user's timestamp will never
+If set to a value less than \f(CW0\fR the user's timestamp will never
expire. This can be used to allow users to create or delete their
own timestamps via \f(CW\*(C`sudo \-v\*(C'\fR and \f(CW\*(C`sudo \-k\*(C'\fR respectively.
-.Ip "passwd_timeout" 12
+.IP "passwd_timeout" 12
.IX Item "passwd_timeout"
Number of minutes before the \fBsudo\fR password prompt times out.
-The default is \f(CW\*(C`@password_timeout@\*(C'\fR, set this to \f(CW\*(C`0\*(C'\fR for no password timeout.
-.Ip "umask" 12
+The default is \f(CW\*(C`@password_timeout@\*(C'\fR, set this to \f(CW0\fR for no password timeout.
+.IP "umask" 12
.IX Item "umask"
Umask to use when running the command. Negate this option or set
it to 0777 to preserve the user's umask. The default is \f(CW\*(C`@sudo_umask@\*(C'\fR.
.PP
\&\fBStrings\fR:
-.Ip "mailsub" 12
+.IP "mailsub" 12
.IX Item "mailsub"
-Subject of the mail sent to the \fImailto\fR user. The escape \f(CW\*(C`%h\*(C'\fR
+Subject of the mail sent to the \fImailto\fR user. The escape \f(CW%h\fR
will expand to the hostname of the machine.
Default is \f(CW\*(C`@mailsub@\*(C'\fR.
-.Ip "badpass_message" 12
+.IP "badpass_message" 12
.IX Item "badpass_message"
Message that is displayed if a user enters an incorrect password.
The default is \f(CW\*(C`@badpass_message@\*(C'\fR unless insults are enabled.
-.Ip "timestampdir" 12
+.IP "timestampdir" 12
.IX Item "timestampdir"
The directory in which \fBsudo\fR stores its timestamp files.
The default is \fI@timedir@\fR.
-.Ip "passprompt" 12
+.IP "timestampowner" 12
+.IX Item "timestampowner"
+The owner of the timestamp directory and the timestamps stored therein.
+The default is \f(CW\*(C`root\*(C'\fR.
+.IP "passprompt" 12
.IX Item "passprompt"
The default prompt to use when asking for a password; can be overridden
-via the \fB\-p\fR option or the \f(CW\*(C`SUDO_PROMPT\*(C'\fR environment variable. Supports
-two escapes: \*(L"%u\*(R" expands to the user's login name and \*(L"%h\*(R" expands
-to the local hostname. The default value is \f(CW\*(C`@passprompt@\*(C'\fR.
-.Ip "runas_default" 12
+via the \fB\-p\fR option or the \f(CW\*(C`SUDO_PROMPT\*(C'\fR environment variable.
+The following percent (`\f(CW\*(C`%\*(C'\fR') escapes are supported:
+.RS 12
+.ie n .IP "%u" 8
+.el .IP "\f(CW%u\fR" 8
+.IX Item "%u"
+expanded to the invoking user's login name
+.ie n .IP "%U" 8
+.el .IP "\f(CW%U\fR" 8
+.IX Item "%U"
+expanded to the login name of the user the command will
+be run as (defaults to root)
+.ie n .IP "%h" 8
+.el .IP "\f(CW%h\fR" 8
+.IX Item "%h"
+expanded to the local hostname without the domain name
+.ie n .IP "%H" 8
+.el .IP "\f(CW%H\fR" 8
+.IX Item "%H"
+expanded to the local hostname including the domain name
+(on if the machine's hostname is fully qualified or the \fIfqdn\fR
+option is set)
+.ie n .IP "\*(C`%%\*(C'" 8
+.el .IP "\f(CW\*(C`%%\*(C'\fR" 8
+.IX Item "%%"
+two consecutive \f(CW\*(C`%\*(C'\fR characters are collaped into a single \f(CW\*(C`%\*(C'\fR character
+.RE
+.RS 12
+.Sp
+The default value is \f(CW\*(C`@passprompt@\*(C'\fR.
+.RE
+.IP "runas_default" 12
.IX Item "runas_default"
The default user to run commands as if the \fB\-u\fR flag is not specified
on the command line. This defaults to \f(CW\*(C`@runas_default@\*(C'\fR.
-.Ip "syslog_goodpri" 12
+Note that if \fIrunas_default\fR is set it \fBmust\fR occur before
+any \f(CW\*(C`Runas_Alias\*(C'\fR specifications.
+.IP "syslog_goodpri" 12
.IX Item "syslog_goodpri"
Syslog priority to use when user authenticates successfully.
Defaults to \f(CW\*(C`@goodpri@\*(C'\fR.
-.Ip "syslog_badpri" 12
+.IP "syslog_badpri" 12
.IX Item "syslog_badpri"
Syslog priority to use when user authenticates unsuccessfully.
Defaults to \f(CW\*(C`@badpri@\*(C'\fR.
-.Ip "editor" 12
+.IP "editor" 12
.IX Item "editor"
A colon (':') separated list of editors allowed to be used with
\&\fBvisudo\fR. \fBvisudo\fR will choose the editor that matches the user's
\&\s-1USER\s0 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.
+.IP "noexec_file" 12
+.IX Item "noexec_file"
+Path to a shared library containing dummy versions of the \fIexecv()\fR,
+\&\fIexecve()\fR and \fIfexecve()\fR library functions that just return an error.
+This is used to implement the \fInoexec\fR functionality on systems that
+support \f(CW\*(C`LD_PRELOAD\*(C'\fR or its equivalent. Defaults to \fI@noexec_file@\fR.
.PP
\&\fBStrings that can be used in a boolean context\fR:
-.Ip "logfile" 12
+.IP "lecture" 12
+.IX Item "lecture"
+This option controls when a short lecture will be printed along with
+the password prompt. It has the following possible values:
+.RS 12
+.IP "never" 8
+.IX Item "never"
+Never lecture the user.
+.IP "once" 8
+.IX Item "once"
+Only lecture the user the first time they run \fBsudo\fR.
+.IP "always" 8
+.IX Item "always"
+Always lecture the user.
+.RE
+.RS 12
+.Sp
+If no value is specified, a value of \fIonce\fR is implied.
+Negating the option results in a value of \fInever\fR being used.
+The default value is \fI@lecture@\fR.
+.RE
+.IP "lecture_file" 12
+.IX Item "lecture_file"
+Path to a file containing an alternate sudo lecture that will
+be used in place of the standard lecture if the named file exists.
+.IP "logfile" 12
.IX Item "logfile"
Path to the \fBsudo\fR log file (not the syslog log file). Setting a path
turns on logging to a file; negating this option turns it off.
-.Ip "syslog" 12
+.IP "syslog" 12
.IX Item "syslog"
Syslog facility if syslog is being used for logging (negate to
disable syslog logging). Defaults to \f(CW\*(C`@logfac@\*(C'\fR.
-.Ip "mailerpath" 12
+.IP "mailerpath" 12
.IX Item "mailerpath"
Path to mail program used to send warning mail.
Defaults to the path to sendmail found at configure time.
-.Ip "mailerflags" 12
+.IP "mailerflags" 12
.IX Item "mailerflags"
Flags to use when invoking mailer. Defaults to \fB\-t\fR.
-.Ip "mailto" 12
+.IP "mailto" 12
.IX Item "mailto"
Address to send warning and error mail to. The address should
be enclosed in double quotes (\f(CW\*(C`"\*(C'\fR) to protect against sudo
interpreting the \f(CW\*(C`@\*(C'\fR sign. Defaults to \f(CW\*(C`@mailto@\*(C'\fR.
-.Ip "exempt_group" 12
+.IP "exempt_group" 12
.IX Item "exempt_group"
Users in this group are exempt from password and \s-1PATH\s0 requirements.
This is not set by default.
-.Ip "verifypw" 12
+.IP "verifypw" 12
.IX Item "verifypw"
This option controls when a password will be required when a user runs
\&\fBsudo\fR with the \fB\-v\fR flag. It has the following possible values:
.RS 12
-.Ip "all" 8
+.IP "all" 8
.IX Item "all"
All the user's \fIsudoers\fR entries for the current host must have
the \f(CW\*(C`NOPASSWD\*(C'\fR flag set to avoid entering a password.
-.Ip "any" 8
+.IP "any" 8
.IX Item "any"
At least one of the user's \fIsudoers\fR entries for the current host
must have the \f(CW\*(C`NOPASSWD\*(C'\fR flag set to avoid entering a password.
-.Ip "never" 8
+.IP "never" 8
.IX Item "never"
The user need never enter a password to use the \fB\-v\fR flag.
-.Ip "always" 8
+.IP "always" 8
.IX Item "always"
The user must always enter a password to use the \fB\-v\fR flag.
.RE
.RS 12
.Sp
-The default value is `all'.
+If no value is specified, a value of \fIall\fR is implied.
+Negating the option results in a value of \fInever\fR being used.
+The default value is \fIall\fR.
.RE
-.Ip "listpw" 12
+.IP "listpw" 12
.IX Item "listpw"
This option controls when a password will be required when a
-user runs \fBsudo\fR with the \fB\-l\fR. It has the following possible values:
+user runs \fBsudo\fR with the \fB\-l\fR flag. It has the following possible values:
.RS 12
-.Ip "all" 8
+.IP "all" 8
.IX Item "all"
All the user's \fIsudoers\fR entries for the current host must have
the \f(CW\*(C`NOPASSWD\*(C'\fR flag set to avoid entering a password.
-.Ip "any" 8
+.IP "any" 8
.IX Item "any"
At least one of the user's \fIsudoers\fR entries for the current host
must have the \f(CW\*(C`NOPASSWD\*(C'\fR flag set to avoid entering a password.
-.Ip "never" 8
+.IP "never" 8
.IX Item "never"
The user need never enter a password to use the \fB\-l\fR flag.
-.Ip "always" 8
+.IP "always" 8
.IX Item "always"
The user must always enter a password to use the \fB\-l\fR flag.
.RE
.RS 12
.Sp
-The default value is `any'.
+If no value is specified, a value of \fIany\fR is implied.
+Negating the option results in a value of \fInever\fR being used.
+The default value is \fIany\fR.
.RE
.PP
\&\fBLists that can be used in a boolean context\fR:
-.Ip "env_check" 12
+.IP "env_check" 12
.IX Item "env_check"
Environment variables to be removed from the user's environment if
the variable's value contains \f(CW\*(C`%\*(C'\fR or \f(CW\*(C`/\*(C'\fR 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
+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 \f(CW\*(C`=\*(C'\fR, \f(CW\*(C`+=\*(C'\fR, \f(CW\*(C`\-=\*(C'\fR, and \f(CW\*(C`!\*(C'\fR operators respectively. The default
-list of environment variable to check is printed when \fBsudo\fR is
+list of environment variables to check is printed when \fBsudo\fR is
run by root with the \fI\-V\fR option.
-.Ip "env_delete" 12
+.IP "env_delete" 12
.IX 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
+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 \f(CW\*(C`=\*(C'\fR, \f(CW\*(C`+=\*(C'\fR, \f(CW\*(C`\-=\*(C'\fR, and
\&\f(CW\*(C`!\*(C'\fR operators respectively. The default list of environment
-variable to remove is printed when \fBsudo\fR is run by root with the
-\&\fI\-V\fR option.
-.Ip "env_keep" 12
+variables to remove is printed when \fBsudo\fR is run by root with the
+\&\fI\-V\fR option. Note that many operating systems will remove potentially
+dangerous variables from the environment of any setuid process (such
+as \fBsudo\fR).
+.IP "env_keep" 12
.IX Item "env_keep"
Environment variables to be preserved in the user's environment
when the \fIenv_reset\fR option is in effect. This allows fine-grained
control over the environment \fBsudo\fR\-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
+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 \f(CW\*(C`=\*(C'\fR, \f(CW\*(C`+=\*(C'\fR, \f(CW\*(C`\-=\*(C'\fR, and
\&\f(CW\*(C`!\*(C'\fR operators respectively. This list has no default members.
.PP
-When logging via \fIsyslog\fR\|(3), \fBsudo\fR accepts the following values for the syslog
-facility (the value of the \fBsyslog\fR Parameter): \fBauthpriv\fR (if your \s-1OS\s0
-supports it), \fBauth\fR, \fBdaemon\fR, \fBuser\fR, \fBlocal0\fR, \fBlocal1\fR, \fBlocal2\fR,
-\&\fBlocal3\fR, \fBlocal4\fR, \fBlocal5\fR, \fBlocal6\fR, and \fBlocal7\fR. The following
-syslog priorities are supported: \fBalert\fR, \fBcrit\fR, \fBdebug\fR, \fBemerg\fR,
-\&\fBerr\fR, \fBinfo\fR, \fBnotice\fR, and \fBwarning\fR.
+When logging via \fIsyslog\fR\|(3), \fBsudo\fR accepts the following values
+for the syslog facility (the value of the \fBsyslog\fR Parameter):
+\&\fBauthpriv\fR (if your \s-1OS\s0 supports it), \fBauth\fR, \fBdaemon\fR, \fBuser\fR,
+\&\fBlocal0\fR, \fBlocal1\fR, \fBlocal2\fR, \fBlocal3\fR, \fBlocal4\fR, \fBlocal5\fR,
+\&\fBlocal6\fR, and \fBlocal7\fR. The following syslog priorities are
+supported: \fBalert\fR, \fBcrit\fR, \fBdebug\fR, \fBemerg\fR, \fBerr\fR, \fBinfo\fR,
+\&\fBnotice\fR, and \fBwarning\fR.
.Sh "User Specification"
.IX Subsection "User Specification"
.Vb 2
-\& User_Spec ::= User_list Host_List '=' Cmnd_Spec_List \e
-\& (':' User_Spec)*
+\& User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \e
+\& (':' Host_List '=' Cmnd_Spec_List)*
.Ve
+.PP
.Vb 2
\& Cmnd_Spec_List ::= Cmnd_Spec |
\& Cmnd_Spec ',' Cmnd_Spec_List
.Ve
+.PP
.Vb 1
-\& Cmnd_Spec ::= Runas_Spec? ('NOPASSWD:' | 'PASSWD:')? Cmnd
+\& Cmnd_Spec ::= Runas_Spec? Tag_Spec* Cmnd
.Ve
+.PP
.Vb 1
\& Runas_Spec ::= '(' Runas_List ')'
.Ve
+.PP
+.Vb 1
+\& Tag_Spec ::= ('NOPASSWD:' | 'PASSWD:' | 'NOEXEC:' | 'EXEC:')
+.Ve
+.PP
A \fBuser specification\fR determines which commands a user may run
(and as what user) on specified hosts. By default, commands are
run as \fBroot\fR, but this can be changed on a per-command basis.
commands that follow it. What this means is that for the entry:
.PP
.Vb 1
-\& dgb boulder = (operator) /bin/ls, /bin/kill, /usr/bin/who
+\& dgb boulder = (operator) /bin/ls, /bin/kill, /usr/bin/lprm
.Ve
+.PP
The user \fBdgb\fR may run \fI/bin/ls\fR, \fI/bin/kill\fR, and
\&\fI/usr/bin/lprm\fR \*(-- but only as \fBoperator\fR. E.g.,
.PP
.Vb 1
-\& sudo -u operator /bin/ls.
+\& $ sudo -u operator /bin/ls.
.Ve
+.PP
It is also possible to override a \f(CW\*(C`Runas_Spec\*(C'\fR later on in an
entry. If we modify the entry like so:
.PP
.Vb 1
\& dgb boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm
.Ve
+.PP
Then user \fBdgb\fR is now allowed to run \fI/bin/ls\fR as \fBoperator\fR,
but \fI/bin/kill\fR and \fI/usr/bin/lprm\fR as \fBroot\fR.
-.Sh "\s-1NOPASSWD\s0 and \s-1PASSWD\s0"
+.Sh "Tag_Spec"
+.IX Subsection "Tag_Spec"
+A command may have zero or more tags associated with it. There are
+four possible tag values, \f(CW\*(C`NOPASSWD\*(C'\fR, \f(CW\*(C`PASSWD\*(C'\fR, \f(CW\*(C`NOEXEC\*(C'\fR, \f(CW\*(C`EXEC\*(C'\fR.
+Once a tag is set on a \f(CW\*(C`Cmnd\*(C'\fR, subsequent \f(CW\*(C`Cmnd\*(C'\fRs in the
+\&\f(CW\*(C`Cmnd_Spec_List\*(C'\fR, inherit the tag unless it is overridden by the
+opposite tag (ie: \f(CW\*(C`PASSWD\*(C'\fR overrides \f(CW\*(C`NOPASSWD\*(C'\fR and \f(CW\*(C`EXEC\*(C'\fR
+overrides \f(CW\*(C`NOEXEC\*(C'\fR).
+.PP
+\fI\s-1NOPASSWD\s0 and \s-1PASSWD\s0\fR
.IX Subsection "NOPASSWD and PASSWD"
+.PP
By default, \fBsudo\fR requires that a user authenticate him or herself
before running a command. This behavior can be modified via the
\&\f(CW\*(C`NOPASSWD\*(C'\fR tag. Like a \f(CW\*(C`Runas_Spec\*(C'\fR, the \f(CW\*(C`NOPASSWD\*(C'\fR tag sets
.Vb 1
\& ray rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm
.Ve
+.PP
would allow the user \fBray\fR to run \fI/bin/kill\fR, \fI/bin/ls\fR, and
\&\fI/usr/bin/lprm\fR as root on the machine rushmore as \fBroot\fR without
authenticating himself. If we only want \fBray\fR to be able to
.Vb 1
\& ray rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm
.Ve
+.PP
Note, however, that the \f(CW\*(C`PASSWD\*(C'\fR tag has no effect on users who are
in the group specified by the exempt_group option.
.PP
\&\f(CW\*(C`sudo \-v\*(C'\fR without a password if the \f(CW\*(C`NOPASSWD\*(C'\fR 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.
-.Sh "Wildcards (aka meta characters):"
-.IX Subsection "Wildcards (aka meta characters):"
-\&\fBsudo\fR allows shell-style \fIwildcards\fR to be used in pathnames
-as well as command line arguments in the \fIsudoers\fR file. Wildcard
-matching is done via the \fB\s-1POSIX\s0\fR \f(CW\*(C`fnmatch(3)\*(C'\fR routine. Note that
-these are \fInot\fR regular expressions.
-.Ip "\f(CW\*(C`*\*(C'\fR" 8
+.PP
+\fI\s-1NOEXEC\s0 and \s-1EXEC\s0\fR
+.IX Subsection "NOEXEC and EXEC"
+.PP
+If sudo has been compiled with \fInoexec\fR support and the underlying
+operating system support it, the \f(CW\*(C`NOEXEC\*(C'\fR tag can be used to prevent
+a dynamically-linked executable from running further commands itself.
+.PP
+In the following example, user \fBaaron\fR may run \fI/usr/bin/more\fR
+and \fI/usr/bin/vi\fR but shell escapes will be disabled.
+.PP
+.Vb 1
+\& aaron shanty = NOEXEC: /usr/bin/more, /usr/bin/vi
+.Ve
+.PP
+See the \*(L"\s-1PREVENTING\s0 \s-1SHELL\s0 \s-1ESCAPES\s0\*(R" section below for more details
+on how \fInoexec\fR works and whether or not it will work on your system.
+.Sh "Wildcards"
+.IX Subsection "Wildcards"
+\&\fBsudo\fR allows shell-style \fIwildcards\fR (aka meta or glob characters)
+to be used in pathnames as well as command line arguments in the
+\&\fIsudoers\fR file. Wildcard matching is done via the \fB\s-1POSIX\s0\fR
+\&\fIfnmatch\fR\|(3) routine. Note that these are \fInot\fR regular expressions.
+.ie n .IP "\*(C`*\*(C'" 8
+.el .IP "\f(CW\*(C`*\*(C'\fR" 8
.IX Item "*"
Matches any set of zero or more characters.
-.Ip "\f(CW\*(C`?\*(C'\fR" 8
+.ie n .IP "\*(C`?\*(C'" 8
+.el .IP "\f(CW\*(C`?\*(C'\fR" 8
.IX Item "?"
Matches any single character.
-.Ip "\f(CW\*(C`[...]\*(C'\fR" 8
+.ie n .IP "\*(C`[...]\*(C'" 8
+.el .IP "\f(CW\*(C`[...]\*(C'\fR" 8
.IX Item "[...]"
Matches any character in the specified range.
-.Ip "\f(CW\*(C`[!...]\*(C'\fR" 8
+.ie n .IP "\*(C`[!...]\*(C'" 8
+.el .IP "\f(CW\*(C`[!...]\*(C'\fR" 8
.IX Item "[!...]"
Matches any character \fBnot\fR in the specified range.
-.Ip "\f(CW\*(C`\ex\*(C'\fR" 8
+.ie n .IP "\*(C`\ex\*(C'" 8
+.el .IP "\f(CW\*(C`\ex\*(C'\fR" 8
.IX Item "x"
For any character \*(L"x\*(R", evaluates to \*(L"x\*(R". This is used to
escape special characters such as: \*(L"*\*(R", \*(L"?\*(R", \*(L"[\*(R", and \*(L"}\*(R".
.PP
Note that a forward slash ('/') will \fBnot\fR be matched by
wildcards used in the pathname. When matching the command
-line arguments, however, as slash \fBdoes\fR get matched by
+line arguments, however, a slash \fBdoes\fR get matched by
wildcards. This is to make a path like:
.PP
.Vb 1
\& /usr/bin/*
.Ve
-match \f(CW\*(C`/usr/bin/who\*(C'\fR but not \f(CW\*(C`/usr/bin/X11/xterm\*(C'\fR.
-.Sh "Exceptions to wildcard rules:"
-.IX Subsection "Exceptions to wildcard rules:"
+.PP
+match \fI/usr/bin/who\fR but not \fI/usr/bin/X11/xterm\fR.
+.PP
+\&\s-1WARNING:\s0 a pathname with wildcards will \fBnot\fR match a user command
+that consists of a relative path. In other words, given the
+following \fIsudoers\fR entry:
+.PP
+.Vb 1
+\& billy workstation = /usr/bin/*
+.Ve
+.PP
+user billy will be able to run any command in /usr/bin as root, such
+as \fI/usr/bin/w\fR. The following two command will be allowed (the first
+assumes that \fI/usr/bin\fR is in the user's path):
+.PP
+.Vb 2
+\& $ sudo w
+\& $ sudo /usr/bin/w
+.Ve
+.PP
+However, this will not:
+.PP
+.Vb 2
+\& $ cd /usr/bin
+\& $ sudo ./w
+.Ve
+.PP
+For this reason you should only \fBgrant\fR access to commands using
+wildcards and never \fBrestrict\fR access using them. This limitation
+will be removed in a future version of \fBsudo\fR.
+.Sh "Exceptions to wildcard rules"
+.IX Subsection "Exceptions to wildcard rules"
The following exceptions apply to the above rules:
-.if n .Ip "\f(CW""""""""\fR" 8
-.el .Ip "\f(CW``''\fR" 8
-.IX Item """""
-If the empty string \f(CW\*(C`""\*(C'\fR is the only command line argument in the
+.ie n .IP """""" 8
+.el .IP "\f(CW``''\fR" 8
+.IX Item """"""
+If the empty string \f(CW""\fR is the only command line argument in the
\&\fIsudoers\fR entry it means that command is not allowed to be run
with \fBany\fR arguments.
-.Sh "Other special characters and reserved words:"
-.IX Subsection "Other special characters and reserved words:"
+.Sh "Other special characters and reserved words"
+.IX Subsection "Other special characters and reserved words"
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.
.PP
-The reserved word \fB\s-1ALL\s0\fR is a built in \fIalias\fR that always causes
+The reserved word \fB\s-1ALL\s0\fR is a built-in \fIalias\fR that always causes
a match to succeed. It can be used wherever one might otherwise
use a \f(CW\*(C`Cmnd_Alias\*(C'\fR, \f(CW\*(C`User_Alias\*(C'\fR, \f(CW\*(C`Runas_Alias\*(C'\fR, or \f(CW\*(C`Host_Alias\*(C'\fR.
You should not try to define your own \fIalias\fR called \fB\s-1ALL\s0\fR as the
-built in alias will be used in preference to your own. Please note
+built-in alias will be used in preference to your own. Please note
that using \fB\s-1ALL\s0\fR can be dangerous since in a command context, it
allows the user to run \fBany\fR command on the system.
.PP
An exclamation point ('!') can be used as a logical \fInot\fR operator
both in an \fIalias\fR and in front of a \f(CW\*(C`Cmnd\*(C'\fR. This allows one to
exclude certain values. Note, however, that using a \f(CW\*(C`!\*(C'\fR in
-conjunction with the built in \f(CW\*(C`ALL\*(C'\fR alias to allow a user to
+conjunction with the built-in \f(CW\*(C`ALL\*(C'\fR alias to allow a user to
run \*(L"all but a few\*(R" commands rarely works as intended (see \s-1SECURITY\s0
\&\s-1NOTES\s0 below).
.PP
The following characters must be escaped with a backslash ('\e') when
used as part of a word (e.g. a username or hostname):
\&'@', '!', '=', ':', ',', '(', ')', '\e'.
+.SH "FILES"
+.IX Header "FILES"
+.Vb 3
+\& @sysconfdir@/sudoers List of who can run what
+\& /etc/group Local groups file
+\& /etc/netgroup List of network groups
+.Ve
.SH "EXAMPLES"
.IX Header "EXAMPLES"
+Since the \fIsudoers\fR file is parsed in a single pass, order is
+important. In general, you should structure \fIsudoers\fR such that
+the \f(CW\*(C`Host_Alias\*(C'\fR, \f(CW\*(C`User_Alias\*(C'\fR, and \f(CW\*(C`Cmnd_Alias\*(C'\fR specifications
+come first, followed by any \f(CW\*(C`Default_Entry\*(C'\fR lines, and finally the
+\&\f(CW\*(C`Runas_Alias\*(C'\fR and user specifications. The basic rule of thumb
+is you cannot reference an Alias that has not already been defined.
+.PP
Below are example \fIsudoers\fR entries. Admittedly, some of
these are a bit contrived. First, we define our \fIaliases\fR:
.PP
\& User_Alias PARTTIMERS = bostley, jwfox, crawl
\& User_Alias WEBMASTERS = will, wendy, wim
.Ve
+.PP
.Vb 3
\& # Runas alias specification
\& Runas_Alias OP = root, operator
\& Runas_Alias DB = oracle, sybase
.Ve
+.PP
.Vb 9
\& # Host alias specification
\& Host_Alias SPARC = bigtime, eclipse, moet, anchor :\e
\& Host_Alias SERVERS = master, mail, www, ns
\& Host_Alias CDROM = orion, perseus, hercules
.Ve
+.PP
.Vb 12
\& # Cmnd alias specification
\& Cmnd_Alias DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\e
\& 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, \e
\& /usr/local/bin/tcsh, /usr/bin/rsh, \e
\& /usr/local/bin/zsh
\& Cmnd_Alias SU = /usr/bin/su
.Ve
+.PP
Here we override some of the compiled in default values. We want
-\&\fBsudo\fR to log via \fIsyslog\fR\|(3) using the \fIauth\fR facility in all cases.
-We don't want to subject the full time staff to the \fBsudo\fR lecture,
-and user \fBmillert\fR need not give a password. In addition, on the
-machines in the \fI\s-1SERVERS\s0\fR \f(CW\*(C`Host_Alias\*(C'\fR, 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.
+\&\fBsudo\fR to log via \fIsyslog\fR\|(3) using the \fIauth\fR facility in all
+cases. We don't want to subject the full time staff to the \fBsudo\fR
+lecture, user \fBmillert\fR need not give a password, and we don't
+want to reset the \f(CW\*(C`LOGNAME\*(C'\fR or \f(CW\*(C`USER\*(C'\fR environment variables when
+running commands as root. Additionally, on the machines in the
+\&\fI\s-1SERVERS\s0\fR \f(CW\*(C`Host_Alias\*(C'\fR, 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.
.PP
-.Vb 5
-\& # Override built in defaults
+.Vb 6
+\& # 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
.Ve
+.PP
The \fIUser specification\fR is the part that actually determines who may
run what.
.PP
\& root ALL = (ALL) ALL
\& %wheel ALL = (ALL) ALL
.Ve
+.PP
We let \fBroot\fR and any user in group \fBwheel\fR run any command on any
host as any user.
.PP
.Vb 1
\& FULLTIMERS ALL = NOPASSWD: ALL
.Ve
+.PP
Full time sysadmins (\fBmillert\fR, \fBmikef\fR, and \fBdowdy\fR) may run any
command on any host without authenticating themselves.
.PP
.Vb 1
\& PARTTIMERS ALL = ALL
.Ve
+.PP
Part time sysadmins (\fBbostley\fR, \fBjwfox\fR, and \fBcrawl\fR) may run any
command on any host but they must authenticate themselves first
(since the entry lacks the \f(CW\*(C`NOPASSWD\*(C'\fR tag).
.Vb 1
\& jack CSNETS = ALL
.Ve
+.PP
The user \fBjack\fR may run any command on the machines in the \fI\s-1CSNETS\s0\fR alias
-(the networks \f(CW\*(C`128.138.243.0\*(C'\fR, \f(CW\*(C`128.138.204.0\*(C'\fR, and \f(CW\*(C`128.138.242.0\*(C'\fR).
-Of those networks, only \f(CW\*(C`128.138.204.0\*(C'\fR has an explicit netmask (in
+(the networks \f(CW128.138.243.0\fR, \f(CW128.138.204.0\fR, and \f(CW128.138.242.0\fR).
+Of those networks, only \f(CW128.138.204.0\fR has an explicit netmask (in
\&\s-1CIDR\s0 notation) indicating it is a class C network. For the other
networks in \fI\s-1CSNETS\s0\fR, the local machine's netmask will be used
during matching.
.Vb 1
\& lisa CUNETS = ALL
.Ve
+.PP
The user \fBlisa\fR may run any command on any host in the \fI\s-1CUNETS\s0\fR alias
-(the class B network \f(CW\*(C`128.138.0.0\*(C'\fR).
+(the class B network \f(CW128.138.0.0\fR).
.PP
.Vb 2
-\& operator ALL = DUMPS, KILL, PRINTING, SHUTDOWN, HALT, REBOOT,\e
-\& /usr/oper/bin/
+\& operator ALL = DUMPS, KILL, SHUTDOWN, HALT, REBOOT, PRINTING,\e
+\& sudoedit /etc/printcap, /usr/oper/bin/
.Ve
+.PP
The \fBoperator\fR user may run commands limited to simple maintenance.
Here, those are commands related to backups, killing processes, the
printing system, shutting down the system, and any commands in the
.Vb 1
\& joe ALL = /usr/bin/su operator
.Ve
+.PP
The user \fBjoe\fR may only \fIsu\fR\|(1) to operator.
.PP
.Vb 1
\& pete HPPA = /usr/bin/passwd [A-z]*, !/usr/bin/passwd root
.Ve
+.PP
The user \fBpete\fR is allowed to change anyone's password except for
root on the \fI\s-1HPPA\s0\fR machines. Note that this assumes \fIpasswd\fR\|(1)
does not take multiple usernames on the command line.
.Vb 1
\& bob SPARC = (OP) ALL : SGI = (OP) ALL
.Ve
+.PP
The user \fBbob\fR may run anything on the \fI\s-1SPARC\s0\fR and \fI\s-1SGI\s0\fR machines
as any user listed in the \fI\s-1OP\s0\fR \f(CW\*(C`Runas_Alias\*(C'\fR (\fBroot\fR and \fBoperator\fR).
.PP
.Vb 1
\& jim +biglab = ALL
.Ve
+.PP
The user \fBjim\fR may run any command on machines in the \fIbiglab\fR netgroup.
\&\fBSudo\fR knows that \*(L"biglab\*(R" is a netgroup due to the '+' prefix.
.PP
.Vb 1
\& +secretaries ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser
.Ve
+.PP
Users in the \fBsecretaries\fR netgroup need to help manage the printers
as well as add and remove users, so they are allowed to run those
commands on all machines.
.Vb 1
\& fred ALL = (DB) NOPASSWD: ALL
.Ve
+.PP
The user \fBfred\fR can run commands as any user in the \fI\s-1DB\s0\fR \f(CW\*(C`Runas_Alias\*(C'\fR
(\fBoracle\fR or \fBsybase\fR) without giving a password.
.PP
.Vb 1
\& john ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root*
.Ve
+.PP
On the \fI\s-1ALPHA\s0\fR machines, user \fBjohn\fR may su to anyone except root
but he is not allowed to give \fIsu\fR\|(1) any flags.
.PP
.Vb 1
\& jen ALL, !SERVERS = ALL
.Ve
+.PP
The user \fBjen\fR may run any command on any machine except for those
in the \fI\s-1SERVERS\s0\fR \f(CW\*(C`Host_Alias\*(C'\fR (master, mail, www and ns).
.PP
.Vb 1
\& jill SERVERS = /usr/bin/, !SU, !SHELLS
.Ve
+.PP
For any machine in the \fI\s-1SERVERS\s0\fR \f(CW\*(C`Host_Alias\*(C'\fR, \fBjill\fR may run
any commands in the directory /usr/bin/ except for those commands
belonging to the \fI\s-1SU\s0\fR and \fI\s-1SHELLS\s0\fR \f(CW\*(C`Cmnd_Aliases\*(C'\fR.
.Vb 1
\& steve CSNETS = (operator) /usr/local/op_commands/
.Ve
+.PP
The user \fBsteve\fR may run any command in the directory /usr/local/op_commands/
but only as user operator.
.PP
.Vb 1
\& matt valkyrie = KILL
.Ve
+.PP
On his personal workstation, valkyrie, \fBmatt\fR needs to be able to
kill hung processes.
.PP
.Vb 1
\& WEBMASTERS www = (www) ALL, (root) /usr/bin/su www
.Ve
+.PP
On the host www, any user in the \fI\s-1WEBMASTERS\s0\fR \f(CW\*(C`User_Alias\*(C'\fR (will,
wendy, and wim), may run any command as user www (which owns the
web pages) or simply \fIsu\fR\|(1) to www.
\& ALL CDROM = NOPASSWD: /sbin/umount /CDROM,\e
\& /sbin/mount -o nosuid\e,nodev /dev/cd0a /CDROM
.Ve
-Any user may mount or unmount a \s-1CD-ROM\s0 on the machines in the \s-1CDROM\s0
+.PP
+Any user may mount or unmount a CD-ROM on the machines in the \s-1CDROM\s0
\&\f(CW\*(C`Host_Alias\*(C'\fR (orion, perseus, hercules) without entering a password.
This is a bit tedious for users to type, so it is a prime candidate
for encapsulating in a shell script.
.Vb 1
\& bill ALL = ALL, !SU, !SHELLS
.Ve
+.PP
Doesn't really prevent \fBbill\fR from running the commands listed in
\&\fI\s-1SU\s0\fR or \fI\s-1SHELLS\s0\fR since he can simply copy those commands to a
different name, or use a shell escape from an editor or other
program. Therefore, these kind of restrictions should be considered
advisory at best (and reinforced by policy).
+.SH "PREVENTING SHELL ESCAPES"
+.IX Header "PREVENTING SHELL ESCAPES"
+Once \fBsudo\fR 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 \fBsudo\fR's restrictions. Common programs
+that permit shell escapes include shells (obviously), editors,
+paginators, mail and terminal programs.
+.PP
+Many systems that support shared libraries have the ability to
+override default library functions by pointing an environment
+variable (usually \f(CW\*(C`LD_PRELOAD\*(C'\fR) to an alternate shared library.
+On such systems, \fBsudo\fR's \fInoexec\fR functionality can be used to
+prevent a program run by 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.
+.PP
+To tell whether or not \fBsudo\fR supports \fInoexec\fR, you can run
+the following as root:
+.PP
+.Vb 1
+\& sudo -V | grep "dummy exec"
+.Ve
+.PP
+If the resulting output contains a line that begins with:
+.PP
+.Vb 1
+\& File containing dummy exec functions:
+.Ve
+.PP
+then \fBsudo\fR 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
+\&\fInoexec\fR will work at compile\-time. \fINoexec\fR should work on
+SunOS, Solaris, *BSD, Linux, \s-1IRIX\s0, Tru64 \s-1UNIX\s0, MacOS X, and HP-UX
+11.x. It is known \fBnot\fR to work on \s-1AIX\s0 and UnixWare. \fINoexec\fR
+is expected to work on most operating systems that support the
+\&\f(CW\*(C`LD_PRELOAD\*(C'\fR 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 \f(CW\*(C`LD_PRELOAD\*(C'\fR is supported.
+.PP
+To enable \fInoexec\fR for a command, use the \f(CW\*(C`NOEXEC\*(C'\fR tag as documented
+in the User Specification section above. Here is that example again:
+.PP
+.Vb 1
+\& aaron shanty = NOEXEC: /usr/bin/more, /usr/bin/vi
+.Ve
+.PP
+This allows user \fBaaron\fR to run \fI/usr/bin/more\fR and \fI/usr/bin/vi\fR
+with \fInoexec\fR 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 \fInoexec\fR you
+can always just try it out and see if it works.
+.PP
+Note that disabling 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 \fBsudoedit\fR.
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+\&\fIrsh\fR\|(1), \fIsu\fR\|(1), \fIfnmatch\fR\|(3), sudo(@mansectsu@), visudo(@mansectsu@)
.SH "CAVEATS"
.IX Header "CAVEATS"
The \fIsudoers\fR file should \fBalways\fR be edited by the \fBvisudo\fR
case), you either need to have the machine's hostname be fully qualified
as returned by the \f(CW\*(C`hostname\*(C'\fR command or use the \fIfqdn\fR option in
\&\fIsudoers\fR.
-.SH "FILES"
-.IX Header "FILES"
-.Vb 3
-\& @sysconfdir@/sudoers List of who can run what
-\& /etc/group Local groups file
-\& /etc/netgroup List of network groups
-.Ve
-.SH "SEE ALSO"
-.IX Header "SEE ALSO"
-\&\fIrsh\fR\|(1), \fIsudo\fR\|(@mansectsu@), \fIvisudo\fR\|(8), \fIsu\fR\|(1), \fIfnmatch\fR\|(3).
+.SH "BUGS"
+.IX Header "BUGS"
+If you feel you have found a bug in \fBsudo\fR, please submit a bug report
+at http://www.sudo.ws/sudo/bugs/
+.SH "SUPPORT"
+.IX Header "SUPPORT"
+Commercial support is available for \fBsudo\fR, see
+http://www.sudo.ws/sudo/support.html for details.
+.PP
+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.
+.SH "DISCLAIMER"
+.IX Header "DISCLAIMER"
+\&\fBSudo\fR is provided ``\s-1AS\s0 \s-1IS\s0'' 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 \s-1LICENSE\s0
+file distributed with \fBsudo\fR or http://www.sudo.ws/sudo/license.html
+for complete details.
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