Form (EBNF). Don't despair if you don't know what EBNF is; it is
fairly simple, and the definitions below are annotated.
- Q\bQu\bui\bic\bck\bk g\bgu\bui\bid\bde\be t\bto\bo E\bEB\bBN\bNF\bF
-
+ Q\bQu\bui\bic\bck\bk g\bgu\bui\bid\bde\be t\bto\bo E\bEB\bBN\bNF\bF
EBNF is a concise and exact way of describing the grammar of a
language. Each EBNF definition is made up of _\bp_\br_\bo_\bd_\bu_\bc_\bt_\bi_\bo_\bn _\br_\bu_\bl_\be_\bs. E.g.,
will use single quotes ('') to designate what is a verbatim character
string (as opposed to a symbol name).
- A\bAl\bli\bia\bas\bse\bes\bs
-
+ A\bAl\bli\bia\bas\bse\bes\bs
There are four kinds of aliases: User_Alias, Runas_Alias, Host_Alias
and Cmnd_Alias.
Runas_Alias ::= NAME '=' Runas_List
+ Host_Alias ::= NAME '=' Host_List
-1.7.0 December 3, 2008 1
+1.7.4 July 21, 2010 1
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- Host_Alias ::= NAME '=' Host_List
Cmnd_Alias ::= NAME '=' Cmnd_List
User_List ::= User |
User ',' User_List
- User ::= '!'* username |
+ User ::= '!'* user name |
'!'* '#'uid |
'!'* '%'group |
'!'* '+'netgroup |
+ '!'* '%:'nonunix_group |
'!'* User_Alias
- A User_List is made up of one or more usernames, uids (prefixed with
+ A User_List is made up of one or more user names, uids (prefixed with
'#'), system groups (prefixed with '%'), netgroups (prefixed with '+')
and User_Aliases. 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 user name, group, netgroup or 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 nonunix_group syntax depends on the underlying implementation. For
+ instance, the QAS AD backend supports the following formats:
+
+ +\bo Group in the same domain: "Group Name"
+
+ +\bo Group in any domain: "Group Name@FULLY.QUALIFIED.DOMAIN"
+
+ +\bo Group SID: "S-1-2-34-5678901234-5678901234-5678901234-567"
+
+ 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
- Runas_Member ::= '!'* username |
- '!'* '#'uid |
- '!'* '%'group |
- '!'* +netgroup |
- '!'* Runas_Alias
- A Runas_List is similar to a User_List except that instead of
- User_Aliases it can contain Runas_Aliases. 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).
- Host_List ::= Host |
- Host ',' Host_List
+1.7.4 July 21, 2010 2
-1.7.0 December 3, 2008 2
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+ Runas_Member ::= '!'* user name |
+ '!'* '#'uid |
+ '!'* '%'group |
+ '!'* +netgroup |
+ '!'* Runas_Alias
+ A Runas_List is similar to a User_List except that instead of
+ User_Aliases it can contain Runas_Aliases. 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. 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 Host_List is made up of one or more hostnames, IP addresses, network
+ A 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 along with the network number, s\bsu\bud\bdo\bo will query each
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. 255.255.255.0 or ffff:ffff:ffff:ffff::), or
- CIDR notation (number of bits, e.g. 24 or 64). A hostname may include
+ CIDR notation (number of bits, e.g. 24 or 64). A host name may include
shell-style wildcards (see the Wildcards section below), but unless the
- hostname command on your machine returns the fully qualified hostname,
- you'll need to use the _\bf_\bq_\bd_\bn option for wildcards to be useful.
+ host name command on your machine returns the fully qualified host
+ name, you'll need to use the _\bf_\bq_\bd_\bn option for wildcards to be useful.
+ Note s\bsu\bud\bdo\bo 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 |
'!'* Cmnd_Alias
A Cmnd_List is a list of one or more commandnames, directories, and
- other aliases. A commandname is a fully qualified filename which may
+ other aliases. A commandname is a fully qualified file name which may
+
+
+
+1.7.4 July 21, 2010 3
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
include shell-style wildcards (see the Wildcards section below). A
- simple filename allows the user to run the command with any arguments
+ 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 "" to indicate
that the command may only be run w\bwi\bit\bth\bho\bou\but\bt command line arguments. A
- directory is a fully qualified pathname ending in a '/'. When you
+ directory is a fully qualified path name ending in a '/'. When you
specify a directory in a Cmnd_List, the user will be able to run any
file within that directory (but not in any subdirectories therein).
to permit a user to run s\bsu\bud\bdo\bo with the -\b-e\be option (or as s\bsu\bud\bdo\boe\bed\bdi\bit\bt). It
may take command line arguments just as a normal command does.
-
-
-
-
-
-
-1.7.0 December 3, 2008 3
-
-
-
-
-
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-
-
- D\bDe\bef\bfa\bau\bul\blt\bts\bs
-
+ D\bDe\bef\bfa\bau\bul\blt\bts\bs
Certain configuration options may be changed from their default values
at runtime via one or more Default_Entry lines. These may affect all
users on any host, all users on a specific host, a specific user, a
is not an error to use the -= operator to remove an element that does
not exist in a list.
- Defaults entries are parsed in the following order: generic, host and
- user Defaults first, then runas Defaults and finally command defaults.
- See "SUDOERS OPTIONS" for a list of supported Defaults parameters.
- U\bUs\bse\ber\br S\bSp\bpe\bec\bci\bif\bfi\bic\bca\bat\bti\bio\bon\bn
- User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \
- (':' Host_List '=' Cmnd_Spec_List)*
+1.7.4 July 21, 2010 4
- Cmnd_Spec_List ::= Cmnd_Spec |
- Cmnd_Spec ',' Cmnd_Spec_List
- Cmnd_Spec ::= Runas_Spec? Tag_Spec* Cmnd
- Runas_Spec ::= '(' Runas_List? (: Runas_List)? ')'
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-1.7.0 December 3, 2008 4
+ Defaults entries are parsed in the following order: generic, host and
+ user Defaults first, then runas Defaults and finally command defaults.
+ See "SUDOERS OPTIONS" for a list of supported Defaults parameters.
+ U\bUs\bse\ber\br S\bSp\bpe\bec\bci\bif\bfi\bic\bca\bat\bti\bio\bon\bn
+ User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \
+ (':' Host_List '=' Cmnd_Spec_List)*
+ Cmnd_Spec_List ::= Cmnd_Spec |
+ Cmnd_Spec ',' Cmnd_Spec_List
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+ Cmnd_Spec ::= Runas_Spec? SELinux_Spec? Tag_Spec* Cmnd
+ Runas_Spec ::= '(' Runas_List? (':' Runas_List)? ')'
+ SELinux_Spec ::= ('ROLE=role' | 'TYPE=type')
Tag_Spec ::= ('NOPASSWD:' | 'PASSWD:' | 'NOEXEC:' | 'EXEC:' |
- 'SETENV:' | 'NOSETENV:' )
+ 'SETENV:' | 'NOSETENV:' | 'LOG_INPUT:' | 'NOLOG_INPUT:' |
+ 'LOG_OUTPUT:' | 'NOLOG_OUTPUT:')
A u\bus\bse\ber\br s\bsp\bpe\bec\bci\bif\bfi\bic\bca\bat\bti\bio\bon\bn determines which commands a user may run (and as
what user) on specified hosts. By default, commands are run as r\bro\boo\bot\bt,
but this can be changed on a per-command basis.
- Let's break that down into its constituent parts:
-
- R\bRu\bun\bna\bas\bs_\b_S\bSp\bpe\bec\bc
+ The basic structure of a user specification is `who = where (as_whom)
+ what'. Let's break that down into its constituent parts:
+ R\bRu\bun\bna\bas\bs_\b_S\bSp\bpe\bec\bc
A Runas_Spec determines the user and/or the group that a command may be
run as. A fully-specified Runas_Spec consists of two Runas_Lists (as
defined above) separated by a colon (':') and enclosed in a set of
$ sudo -u operator /bin/ls.
+
+
+
+1.7.4 July 21, 2010 5
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
It is also possible to override a Runas_Spec later on in an entry. If
we modify the entry like so:
device file with the dialer group. Note that in this example only the
group will be set, the command still runs as user t\btc\bcm\bm.
-
-
-
-1.7.0 December 3, 2008 5
-
-
-
-
-
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-
-
tcm boulder = (:dialer) /usr/bin/tip, /usr/bin/cu, \
/usr/local/bin/minicom
- T\bTa\bag\bg_\b_S\bSp\bpe\bec\bc
+ S\bSE\bEL\bLi\bin\bnu\bux\bx_\b_S\bSp\bpe\bec\bc
+ On systems with SELinux support, _\bs_\bu_\bd_\bo_\be_\br_\bs 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 _\bs_\bu_\bd_\bo_\be_\br_\bs. A role or type specified on the command line,
+ however, will supercede the values in _\bs_\bu_\bd_\bo_\be_\br_\bs.
+ T\bTa\bag\bg_\b_S\bSp\bpe\bec\bc
A command may have zero or more tags associated with it. There are
- eight possible tag values, NOPASSWD, PASSWD, NOEXEC, EXEC, SETENV and
- NOSETENV. Once a tag is set on a Cmnd, subsequent Cmnds in the
- Cmnd_Spec_List, inherit the tag unless it is overridden by the opposite
- tag (i.e.: PASSWD overrides NOPASSWD and NOEXEC overrides EXEC).
+ eight possible tag values, NOPASSWD, PASSWD, NOEXEC, EXEC, SETENV,
+ NOSETENV, LOG_INPUT, NOLOG_INPUT, LOG_OUTPUT and NOLOG_OUTPUT. Once a
+ tag is set on a Cmnd, subsequent Cmnds in the Cmnd_Spec_List, inherit
+ the tag unless it is overridden by the opposite tag (i.e.: PASSWD
+ overrides NOPASSWD and NOEXEC overrides EXEC).
_\bN_\bO_\bP_\bA_\bS_\bS_\bW_\bD _\ba_\bn_\bd _\bP_\bA_\bS_\bS_\bW_\bD
ray rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm
Note, however, that the PASSWD tag has no effect on users who are in
+
+
+
+1.7.4 July 21, 2010 6
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
the group specified by the _\be_\bx_\be_\bm_\bp_\bt_\b__\bg_\br_\bo_\bu_\bp option.
By default, if the NOPASSWD tag is applied to any of the entries for a
_\bS_\bE_\bT_\bE_\bN_\bV _\ba_\bn_\bd _\bN_\bO_\bS_\bE_\bT_\bE_\bN_\bV
+ These tags override the value of the _\bs_\be_\bt_\be_\bn_\bv option on a per-command
+ basis. Note that if SETENV has been set for a command, any environment
+ variables set on the command line way are not subject to the
+ restrictions imposed by _\be_\bn_\bv_\b__\bc_\bh_\be_\bc_\bk, _\be_\bn_\bv_\b__\bd_\be_\bl_\be_\bt_\be, or _\be_\bn_\bv_\b__\bk_\be_\be_\bp. As such,
+ only trusted users should be allowed to set variables in this manner.
+ If the command matched is A\bAL\bLL\bL, the SETENV tag is implied for that
+ command; this default may be overridden by use of the NOSETENV tag.
+ _\bL_\bO_\bG_\b__\bI_\bN_\bP_\bU_\bT _\ba_\bn_\bd _\bN_\bO_\bL_\bO_\bG_\b__\bI_\bN_\bP_\bU_\bT
+ These tags override the value of the _\bl_\bo_\bg_\b__\bi_\bn_\bp_\bu_\bt option on a per-command
+ basis. For more information, see the description of _\bl_\bo_\bg_\b__\bi_\bn_\bp_\bu_\bt in the
+ "SUDOERS OPTIONS" section below.
-1.7.0 December 3, 2008 6
+ _\bL_\bO_\bG_\b__\bO_\bU_\bT_\bP_\bU_\bT _\ba_\bn_\bd _\bN_\bO_\bL_\bO_\bG_\b__\bO_\bU_\bT_\bP_\bU_\bT
+ These tags override the value of the _\bl_\bo_\bg_\b__\bo_\bu_\bt_\bp_\bu_\bt option on a per-command
+ basis. For more information, see the description of _\bl_\bo_\bg_\b__\bo_\bu_\bt_\bp_\bu_\bt in the
+ "SUDOERS OPTIONS" section below.
+ W\bWi\bil\bld\bdc\bca\bar\brd\bds\bs
+ s\bsu\bud\bdo\bo allows shell-style _\bw_\bi_\bl_\bd_\bc_\ba_\br_\bd_\bs (aka meta or glob characters) to be
+ used in host names, path names and command line arguments in the
+ _\bs_\bu_\bd_\bo_\be_\br_\bs file. Wildcard matching is done via the P\bPO\bOS\bSI\bIX\bX _\bg_\bl_\bo_\bb(3) and
+ _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3) routines. Note that these are _\bn_\bo_\bt regular expressions.
+ * Matches any set of zero or more characters.
+ ? Matches any single character.
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- These tags override the value of the _\bs_\be_\bt_\be_\bn_\bv option on a per-command
- basis. Note that if SETENV has been set for a command, any environment
- variables set on the command line way are not subject to the
- restrictions imposed by _\be_\bn_\bv_\b__\bc_\bh_\be_\bc_\bk, _\be_\bn_\bv_\b__\bd_\be_\bl_\be_\bt_\be, or _\be_\bn_\bv_\b__\bk_\be_\be_\bp. As such,
- only trusted users should be allowed to set variables in this manner.
- If the command matched is A\bAL\bLL\bL, the SETENV tag is implied for that
- command; this default may be overridden by use of the UNSETENV tag.
+1.7.4 July 21, 2010 7
- W\bWi\bil\bld\bdc\bca\bar\brd\bds\bs
- s\bsu\bud\bdo\bo allows shell-style _\bw_\bi_\bl_\bd_\bc_\ba_\br_\bd_\bs (aka meta or glob characters) to be
- used in hostnames, pathnames and command line arguments in the _\bs_\bu_\bd_\bo_\be_\br_\bs
- file. Wildcard matching is done via the P\bPO\bOS\bSI\bIX\bX _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3) routine.
- Note that these are _\bn_\bo_\bt regular expressions.
- * Matches any set of zero or more characters.
- ? Matches any single character.
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
[...] Matches any character in the specified range.
\x For any character "x", evaluates to "x". This is used to
escape special characters such as: "*", "?", "[", and "}".
- POSIX character classes may also be used if your system's _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3)
- function supports them. However, because the ':' character has special
- meaning in _\bs_\bu_\bd_\bo_\be_\br_\bs, it must be escaped. For example:
+ POSIX character classes may also be used if your system's _\bg_\bl_\bo_\bb(3) and
+ _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3) functions support them. However, because the ':' character
+ has special meaning in _\bs_\bu_\bd_\bo_\be_\br_\bs, it must be escaped. For example:
/bin/ls [[\:alpha\:]]*
- Would match any filename beginning with a letter.
+ Would match any file name beginning with a letter.
Note that a forward slash ('/') will n\bno\bot\bt be matched by wildcards used
- in the pathname. When matching the command line arguments, however, a
+ in the path name. When matching the command line arguments, however, a
slash d\bdo\boe\bes\bs get matched by wildcards. This is to make a path like:
/usr/bin/*
match _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bw_\bh_\bo but not _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bX_\b1_\b1_\b/_\bx_\bt_\be_\br_\bm.
- E\bEx\bxc\bce\bep\bpt\bti\bio\bon\bns\bs t\bto\bo w\bwi\bil\bld\bdc\bca\bar\brd\bd r\bru\bul\ble\bes\bs
-
+ E\bEx\bxc\bce\bep\bpt\bti\bio\bon\bns\bs t\bto\bo w\bwi\bil\bld\bdc\bca\bar\brd\bd r\bru\bul\ble\bes\bs
The following exceptions apply to the above rules:
"" If the empty string "" is the only command line argument in the
_\bs_\bu_\bd_\bo_\be_\br_\bs entry it means that command is not allowed to be run
with a\ban\bny\by arguments.
- I\bIn\bnc\bcl\blu\bud\bdi\bin\bng\bg o\bot\bth\bhe\ber\br f\bfi\bil\ble\bes\bs f\bfr\bro\bom\bm w\bwi\bit\bth\bhi\bin\bn s\bsu\bud\bdo\boe\ber\brs\bs
-
+ I\bIn\bnc\bcl\blu\bud\bdi\bin\bng\bg o\bot\bth\bhe\ber\br f\bfi\bil\ble\bes\bs f\bfr\bro\bom\bm w\bwi\bit\bth\bhi\bin\bn s\bsu\bud\bdo\boe\ber\brs\bs
It is possible to include other _\bs_\bu_\bd_\bo_\be_\br_\bs files from within the _\bs_\bu_\bd_\bo_\be_\br_\bs
- file currently being parsed using the #include directive, similar to
+ file currently being parsed using the #include and #includedir
+ directives.
+ This can be used, for example, to keep a site-wide _\bs_\bu_\bd_\bo_\be_\br_\bs file in
+ addition to a local, per-machine file. For the sake of this example
+ the site-wide _\bs_\bu_\bd_\bo_\be_\br_\bs will be _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs and the per-machine one will
+ be _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl. To include _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl from within
+ _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs we would use the following line in _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs:
+ #include /etc/sudoers.local
-1.7.0 December 3, 2008 7
+ When s\bsu\bud\bdo\bo reaches this line it will suspend processing of the current
+ file (_\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs) and switch to _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl. Upon reaching
+ the end of _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl, the rest of _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs 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 %h escape, signifying the short form of
+ the host name. I.e., if the machine's host name is "xerxes", then
+
+ #include /etc/sudoers.%h
+
+
+
+1.7.4 July 21, 2010 8
SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- the one used by the C preprocessor. This is useful, for example, for
- keeping a site-wide _\bs_\bu_\bd_\bo_\be_\br_\bs file in addition to a per-machine local
- one. For the sake of this example the site-wide _\bs_\bu_\bd_\bo_\be_\br_\bs will be
- _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs and the per-machine one will be _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl. To
- include _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl from _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs we would use the following
- line in _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs:
+ will cause s\bsu\bud\bdo\bo to include the file _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bx_\be_\br_\bx_\be_\bs.
- #include /etc/sudoers.local
+ The #includedir directive can be used to create a _\bs_\bu_\bd_\bo_\b._\bd directory that
+ the system package manager can drop _\bs_\bu_\bd_\bo_\be_\br_\bs rules into as part of
+ package installation. For example, given:
- When s\bsu\bud\bdo\bo reaches this line it will suspend processing of the current
- file (_\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs) and switch to _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl. Upon reaching
- the end of _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bl_\bo_\bc_\ba_\bl, the rest of _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs 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.
+ #includedir /etc/sudoers.d
+
+ s\bsu\bud\bdo\bo will read each file in _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bd, skipping file names that
+ end in ~ or contain a . character to avoid causing problems with
+ package manager or editor temporary/backup files. Files are parsed in
+ sorted lexical order. That is, _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bd_\b/_\b0_\b1_\b__\bf_\bi_\br_\bs_\bt will be parsed
+ before _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bd_\b/_\b1_\b0_\b__\bs_\be_\bc_\bo_\bn_\bd. Be aware that because the sorting is
+ lexical, not numeric, _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bd_\b/_\b1_\b__\bw_\bh_\bo_\bo_\bp_\bs would be loaded a\baf\bft\bte\ber\br
+ _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs_\b._\bd_\b/_\b1_\b0_\b__\bs_\be_\bc_\bo_\bn_\bd. Using a consistent number of leading zeroes
+ in the file names can be used to avoid such problems.
- O\bOt\bth\bhe\ber\br s\bsp\bpe\bec\bci\bia\bal\bl c\bch\bha\bar\bra\bac\bct\bte\ber\brs\bs a\ban\bnd\bd r\bre\bes\bse\ber\brv\bve\bed\bd w\bwo\bor\brd\bds\bs
+ Note that unlike files included via #include, v\bvi\bis\bsu\bud\bdo\bo will not edit the
+ files in a #includedir directory unless one of them contains a syntax
+ error. It is still possible to run v\bvi\bis\bsu\bud\bdo\bo with the -f flag to edit the
+ files directly.
+ O\bOt\bth\bhe\ber\br s\bsp\bpe\bec\bci\bia\bal\bl c\bch\bha\bar\bra\bac\bct\bte\ber\brs\bs a\ban\bnd\bd r\bre\bes\bse\ber\brv\bve\bed\bd w\bwo\bor\brd\bds\bs
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
characters in a _\bU_\bs_\be_\br _\bS_\bp_\be_\bc_\bi_\bf_\bi_\bc_\ba_\bt_\bi_\bo_\bn ('=', ':', '(', ')') is optional.
The following characters must be escaped with a backslash ('\') when
- used as part of a word (e.g. a username or hostname): '@', '!', '=',
+ used as part of a word (e.g. a user name or host name): '@', '!', '=',
':', ',', '(', ')', '\'.
-S\bSU\bUD\bDO\bOE\bER\bRS\bS O\bOP\bPT\bTI\bIO\bON\bNS\bS
- s\bsu\bud\bdo\bo's behavior can be modified by Default_Entry lines, as explained
- earlier. A list of all supported Defaults parameters, grouped by type,
- are listed below.
- F\bFl\bla\bag\bgs\bs:
-1.7.0 December 3, 2008 8
+1.7.4 July 21, 2010 9
SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- always_set_home If set, s\bsu\bud\bdo\bo will set the HOME environment variable to
- the home directory of the target user (which is root
+S\bSU\bUD\bDO\bOE\bER\bRS\bS O\bOP\bPT\bTI\bIO\bON\bNS\bS
+ s\bsu\bud\bdo\bo's behavior can be modified by Default_Entry lines, as explained
+ earlier. A list of all supported Defaults parameters, grouped by type,
+ are listed below.
+
+ B\bBo\boo\bol\ble\bea\ban\bn F\bFl\bla\bag\bgs\bs:
+
+ always_set_home If enabled, s\bsu\bud\bdo\bo will set the HOME environment variable
+ to the home directory of the target user (which is root
unless the -\b-u\bu option is used). This effectively means
- that the -\b-H\bH option is always implied. This flag is _\bo_\bf_\bf
- by default.
+ that the -\b-H\bH option is always implied. Note that HOME
+ is already set when the the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt option is
+ enabled, so _\ba_\bl_\bw_\ba_\by_\bs_\b__\bs_\be_\bt_\b__\bh_\bo_\bm_\be is only effective for
+ configurations where _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt is disabled. This flag
+ is _\bo_\bf_\bf by default.
authenticate If set, users must authenticate themselves via a
password (or other means of authentication) before they
begins closing open file descriptors. This flag is _\bo_\bf_\bf
by default.
+ compress_io If set, and s\bsu\bud\bdo\bo is configured to log a command's input
+ or output, the I/O logs will be compressed using z\bzl\bli\bib\bb.
+ This flag is _\bo_\bn by default when s\bsu\bud\bdo\bo is compiled with
+ z\bzl\bli\bib\bb support.
+
env_editor If set, v\bvi\bis\bsu\bud\bdo\bo 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
specified in editor. This flag is _\bo_\bf_\bf by default.
env_reset If set, s\bsu\bud\bdo\bo will reset the environment to only contain
- the LOGNAME, SHELL, USER, USERNAME and the SUDO_*
+ the LOGNAME, MAIL, SHELL, USER, USERNAME and the SUDO_*
variables. Any variables in the caller's environment
that match the env_keep and env_check lists are then
added. The default contents of the env_keep and
its value will be used for the PATH environment
variable. This flag is _\bo_\bn by default.
- fqdn Set this flag if you want to put fully qualified
- hostnames in the _\bs_\bu_\bd_\bo_\be_\br_\bs 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 _\bf_\bq_\bd_\bn requires s\bsu\bud\bdo\bo to make DNS
- lookups which may make s\bsu\bud\bdo\bo 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 (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 hostname command) is already fully
- qualified you shouldn't need to set _\bf_\bq_\bd_\bn. This flag is
- _\bo_\bf_\bf by default.
-
+ fast_glob Normally, s\bsu\bud\bdo\bo uses the _\bg_\bl_\bo_\bb(3) function to do shell-
-1.7.0 December 3, 2008 9
+1.7.4 July 21, 2010 10
SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+ style globbing when matching path names. However,
+ since it accesses the file system, _\bg_\bl_\bo_\bb(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 _\bf_\ba_\bs_\bt_\b__\bg_\bl_\bo_\bb
+ option causes s\bsu\bud\bdo\bo to use the _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3) function,
+ which does not access the file system to do its
+ matching. The disadvantage of _\bf_\ba_\bs_\bt_\b__\bg_\bl_\bo_\bb is that it is
+ unable to match relative path names such as _\b._\b/_\bl_\bs or
+ _\b._\b._\b/_\bb_\bi_\bn_\b/_\bl_\bs. This has security implications when path
+ names that include globbing characters are used with
+ the negation operator, '!', as such rules can be
+ trivially bypassed. As such, this option should not be
+ used when _\bs_\bu_\bd_\bo_\be_\br_\bs contains rules that contain negated
+ path names which include globbing characters. This
+ flag is _\bo_\bf_\bf by default.
+
+ fqdn Set this flag if you want to put fully qualified host
+ names in the _\bs_\bu_\bd_\bo_\be_\br_\bs 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 _\bf_\bq_\bd_\bn requires s\bsu\bud\bdo\bo to make DNS lookups
+ which may make s\bsu\bud\bdo\bo 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 (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 hostname command) is already fully
+ qualified you shouldn't need to set _\bf_\bq_\bd_\bn. This flag is
+ _\bo_\bf_\bf by default.
+
ignore_dot If set, s\bsu\bud\bdo\bo will ignore '.' or '' (current dir) in the
PATH environment variable; the PATH itself is not
modified. This flag is _\bo_\bf_\bf by default.
insults If set, s\bsu\bud\bdo\bo will insult users when they enter an
incorrect password. This flag is _\bo_\bf_\bf by default.
- log_host If set, the hostname will be logged in the (non-syslog)
- s\bsu\bud\bdo\bo log file. This flag is _\bo_\bf_\bf by default.
+ log_host If set, the host name will be logged in the (non-
+
+
+
+1.7.4 July 21, 2010 11
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
+ syslog) s\bsu\bud\bdo\bo log file. This flag is _\bo_\bf_\bf by default.
log_year If set, the four-digit year will be logged in the (non-
syslog) s\bsu\bud\bdo\bo log file. This flag is _\bo_\bf_\bf by default.
invoking user is not in the _\bs_\bu_\bd_\bo_\be_\br_\bs file. This flag is
_\bo_\bn by default.
-
-
-1.7.0 December 3, 2008 10
-
-
-
-
-
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-
-
noexec If set, all commands run via s\bsu\bud\bdo\bo will behave as if the
NOEXEC tag has been set, unless overridden by a EXEC
tag. See the description of _\bN_\bO_\bE_\bX_\bE_\bC _\ba_\bn_\bd _\bE_\bX_\bE_\bC below as
passprompt_override
The password prompt specified by _\bp_\ba_\bs_\bs_\bp_\br_\bo_\bm_\bp_\bt will
- normally only be used if the passwod prompt provided by
- systems such as PAM matches the string "Password:". If
- _\bp_\ba_\bs_\bs_\bp_\br_\bo_\bm_\bp_\bt_\b__\bo_\bv_\be_\br_\br_\bi_\bd_\be is set, _\bp_\ba_\bs_\bs_\bp_\br_\bo_\bm_\bp_\bt will always be
- used. This flag is _\bo_\bf_\bf by default.
+ normally only be used if the password prompt provided
+ by systems such as PAM matches the string "Password:".
+
+
+
+1.7.4 July 21, 2010 12
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
+ If _\bp_\ba_\bs_\bs_\bp_\br_\bo_\bm_\bp_\bt_\b__\bo_\bv_\be_\br_\br_\bi_\bd_\be is set, _\bp_\ba_\bs_\bs_\bp_\br_\bo_\bm_\bp_\bt will always
+ be used. This flag is _\bo_\bf_\bf by default.
- preserve_groups By default s\bsu\bud\bdo\bo will initialize the group vector to the
- list of groups the target user is in. When
+ preserve_groups By default, s\bsu\bud\bdo\bo will initialize the group vector to
+ the list of groups the target user is in. When
_\bp_\br_\be_\bs_\be_\br_\bv_\be_\b__\bg_\br_\bo_\bu_\bp_\bs 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 _\bo_\bf_\bf by default.
+ pwfeedback By default, s\bsu\bud\bdo\bo 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 s\bsu\bud\bdo\bo has hung at
+ this point. When _\bp_\bw_\bf_\be_\be_\bd_\bb_\ba_\bc_\bk is set, s\bsu\bud\bdo\bo 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 _\bo_\bf_\bf by default.
+
requiretty If set, s\bsu\bud\bdo\bo will only run when the user is logged in
to a real tty. When this flag is set, s\bsu\bud\bdo\bo can only be
run from a login session and not via other means such
this prevents users from "chaining" s\bsu\bud\bdo\bo commands to
get a root shell by doing something like "sudo sudo
/bin/sh". Note, however, that turning off _\br_\bo_\bo_\bt_\b__\bs_\bu_\bd_\bo
- will also prevent root and from running s\bsu\bud\bdo\boe\bed\bdi\bit\bt.
+ will also prevent root from running s\bsu\bud\bdo\boe\bed\bdi\bit\bt.
Disabling _\br_\bo_\bo_\bt_\b__\bs_\bu_\bd_\bo provides no real additional
security; it exists purely for historical reasons.
This flag is _\bo_\bn by default.
instead of the password of the invoking user. This
flag is _\bo_\bf_\bf by default.
+ set_home If enabled and s\bsu\bud\bdo\bo is invoked with the -\b-s\bs option the
+ HOME environment variable will be set to the home
+ directory of the target user (which is root unless the
+ -\b-u\bu option is used). This effectively makes the -\b-s\bs
+ option imply -\b-H\bH. Note that HOME is already set when
+ the the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt option is enabled, so _\bs_\be_\bt_\b__\bh_\bo_\bm_\be is
+ only effective for configurations where _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt is
+ disabled. This flag is _\bo_\bf_\bf by default.
+
+ set_logname Normally, s\bsu\bud\bdo\bo will set the LOGNAME, USER and USERNAME
-1.7.0 December 3, 2008 11
+1.7.4 July 21, 2010 13
SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- set_home If set and s\bsu\bud\bdo\bo is invoked with the -\b-s\bs option the HOME
- environment variable will be set to the home directory
- of the target user (which is root unless the -\b-u\bu option
- is used). This effectively makes the -\b-s\bs option imply
- -\b-H\bH. This flag is _\bo_\bf_\bf by default.
-
- set_logname Normally, s\bsu\bud\bdo\bo will set the LOGNAME, USER and USERNAME
environment variables to the name of the target user
(usually root unless the -\b-u\bu option is given). However,
since some programs (including the RCS revision control
This can be done by negating the set_logname option.
Note that if the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt option has not been
disabled, entries in the _\be_\bn_\bv_\b__\bk_\be_\be_\bp list will override
- the value of _\bs_\be_\bt_\b__\bl_\bo_\bg_\bn_\ba_\bm_\be. This flag is _\bo_\bf_\bf by default.
+ the value of _\bs_\be_\bt_\b__\bl_\bo_\bg_\bn_\ba_\bm_\be. This flag is _\bo_\bn by default.
setenv Allow the user to disable the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt option from the
command line. Additionally, environment variables set
targetpw If set, s\bsu\bud\bdo\bo will prompt for the password of the user
specified by the -\b-u\bu option (defaults to root) instead
- of the password of the invoking user. Note that this
- precludes the use of a uid not listed in the passwd
- database as an argument to the -\b-u\bu option. This flag is
- _\bo_\bf_\bf by default.
+ 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\bu option. This flag is _\bo_\bf_\bf by default.
- tty_tickets If set, users must authenticate on a per-tty basis.
- Normally, s\bsu\bud\bdo\bo uses a directory in the ticket dir with
- the same name as the user running it. With this flag
- enabled, s\bsu\bud\bdo\bo will use a file named for the tty the
+ log_input If set, s\bsu\bud\bdo\bo will run the command in a _\bp_\bs_\be_\bu_\bd_\bo _\bt_\bt_\by 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 _\b/_\bv_\ba_\br_\b/_\bl_\bo_\bg_\b/_\bs_\bu_\bd_\bo_\b-_\bi_\bo directory using
+ a unique session ID that is included in the normal s\bsu\bud\bdo\bo
+ log line, prefixed with _\bT_\bS_\bI_\bD_\b=.
-1.7.0 December 3, 2008 12
+
+
+1.7.4 July 21, 2010 14
SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- user is logged in on in that directory. This flag is
- _\bo_\bf_\bf by default.
+ log_output If set, s\bsu\bud\bdo\bo will run the command in a _\bp_\bs_\be_\bu_\bd_\bo _\bt_\bt_\by and
+ log all output that is sent to the screen, similar to
+ the _\bs_\bc_\br_\bi_\bp_\bt(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 _\b/_\bv_\ba_\br_\b/_\bl_\bo_\bg_\b/_\bs_\bu_\bd_\bo_\b-_\bi_\bo directory
+ using a unique session ID that is included in the
+ normal s\bsu\bud\bdo\bo log line, prefixed with _\bT_\bS_\bI_\bD_\b=.
+
+ Output logs may be viewed with the _\bs_\bu_\bd_\bo_\br_\be_\bp_\bl_\ba_\by(1m)
+ utility, which can also be used to list or search the
+ available logs.
+
+ tty_tickets If set, users must authenticate on a per-tty basis.
+ With this flag enabled, s\bsu\bud\bdo\bo 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 _\bo_\bn by default.
+
+ umask_override If set, s\bsu\bud\bdo\bo will set the umask as specified by _\bs_\bu_\bd_\bo_\be_\br_\bs
+ without modification. This makes it possible to
+ specify a more permissive umask in _\bs_\bu_\bd_\bo_\be_\br_\bs than the
+ user's own umask and matches historical behavior. If
+ _\bu_\bm_\ba_\bs_\bk_\b__\bo_\bv_\be_\br_\br_\bi_\bd_\be is not set, s\bsu\bud\bdo\bo will set the umask to
+ be the union of the user's umask and what is specified
+ in _\bs_\bu_\bd_\bo_\be_\br_\bs. This flag is _\bo_\bf_\bf by default.
use_loginclass If set, s\bsu\bud\bdo\bo will apply the defaults specified for the
target user's login class if one exists. Only
available if s\bsu\bud\bdo\bo is configured with the
--with-logincap option. This flag is _\bo_\bf_\bf by default.
+ use_pty If set, s\bsu\bud\bdo\bo will run the command in a pseudo-pty even
+ if no I/O logging is being gone. A malicious program
+ run under s\bsu\bud\bdo\bo 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.
+
visiblepw By default, s\bsu\bud\bdo\bo will refuse to run if the user must
enter a password but it is not possible to disable echo
on the terminal. If the _\bv_\bi_\bs_\bi_\bb_\bl_\be_\bp_\bw flag is set, s\bsu\bud\bdo\bo
closefrom Before it executes a command, s\bsu\bud\bdo\bo will close all open
file descriptors other than standard input, standard
+
+
+
+1.7.4 July 21, 2010 15
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
output and standard error (ie: file descriptors 0-2).
The _\bc_\bl_\bo_\bs_\be_\bf_\br_\bo_\bm option can be used to specify a different
file descriptor at which to start closing. The default
the option to disable word wrap).
passwd_timeout Number of minutes before the s\bsu\bud\bdo\bo password prompt times
- out. The default is 5; set this to 0 for no password
- timeout.
+ out, or 0 for no timeout. The timeout may include a
+ fractional component if minute granularity is
+ insufficient, for example 2.5. The default is 5.
timestamp_timeout
Number of minutes that can elapse before s\bsu\bud\bdo\bo will ask
- for a passwd again. The default is 5. Set this to 0
- to always prompt for a password. If set to a value
- less than 0 the user's timestamp will never expire.
- This can be used to allow users to create or delete
- their own timestamps via sudo -v and sudo -k
+ for a passwd again. The timeout may include a
+ fractional component if minute granularity is
+ insufficient, for example 2.5. The default is 5. Set
+ this to 0 to always prompt for a password. If set to a
+ value less than 0 the user's timestamp will never
+ expire. This can be used to allow users to create or
+ delete their own timestamps via sudo -v and sudo -k
respectively.
umask 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 0022. This guarantees that s\bsu\bud\bdo\bo never
-
-
-
-1.7.0 December 3, 2008 13
-
-
-
-
-
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-
-
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
used with v\bvi\bis\bsu\bud\bdo\bo. v\bvi\bis\bsu\bud\bdo\bo 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 the path to vi on
- your system.
+ and is executable. The default is "vi".
+
+
+
+
+1.7.4 July 21, 2010 16
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
mailsub Subject of the mail sent to the _\bm_\ba_\bi_\bl_\bt_\bo user. The escape
- %h will expand to the hostname of the machine. Default
- is *** SECURITY information for %h ***.
+ %h will expand to the host name of the machine.
+ Default is *** SECURITY information for %h ***.
noexec_file Path to a shared library containing dummy versions of
the _\be_\bx_\be_\bc_\bv_\b(_\b), _\be_\bx_\be_\bc_\bv_\be_\b(_\b) and _\bf_\be_\bx_\be_\bc_\bv_\be_\b(_\b) library functions
environment variable. The following percent (`%')
escapes are supported:
- %H expanded to the local hostname including the domain
- name (on if the machine's hostname is fully
+ %H expanded to the local host name including the
+ domain name (on if the machine's host name is fully
qualified or the _\bf_\bq_\bd_\bn option is set)
- %h expanded to the local hostname without the domain
+ %h expanded to the local host name without the domain
name
%p expanded to the user whose password is being asked
The default value is Password:.
-
-
-1.7.0 December 3, 2008 14
-
-
-
-
-
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
-
+ role 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 _\bs_\bu_\bd_\bo_\be_\br_\bs or
+ via command line options. This option is only
+ available whe s\bsu\bud\bdo\bo is built with SELinux support.
runas_default The default user to run commands as if the -\b-u\bu option is
not specified on the command line. This defaults to
syslog_goodpri Syslog priority to use when user authenticates
successfully. Defaults to notice.
+
+
+
+1.7.4 July 21, 2010 17
+
+
+
+
+
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
sudoers_locale Locale to use when parsing the sudoers file. Note that
changing the locale may affect how sudoers is
interpreted. Defaults to "C".
timestampdir The directory in which s\bsu\bud\bdo\bo stores its timestamp files.
- The default is _\b/_\bv_\ba_\br_\b/_\br_\bu_\bn_\b/_\bs_\bu_\bd_\bo.
+ The default is _\b/_\bv_\ba_\br_\b/_\ba_\bd_\bm_\b/_\bs_\bu_\bd_\bo.
timestampowner The owner of the timestamp directory and the timestamps
stored therein. The default is root.
+ type 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 _\bs_\bu_\bd_\bo_\be_\br_\bs or
+ via command line options. This option is only
+ available whe s\bsu\bud\bdo\bo is built with SELinux support.
+
S\bSt\btr\bri\bin\bng\bgs\bs t\bth\bha\bat\bt c\bca\ban\bn b\bbe\be u\bus\bse\bed\bd i\bin\bn a\ba b\bbo\boo\bol\ble\bea\ban\bn c\bco\bon\bnt\bte\bex\bxt\bt:
askpass The _\ba_\bs_\bk_\bp_\ba_\bs_\bs option specifies the fully qualified path to a
env_file The _\be_\bn_\bv_\b__\bf_\bi_\bl_\be 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 be of
- the form VARIABLE=value. Variables in this file are
- subject to other s\bsu\bud\bdo\bo environment settings such as _\be_\bn_\bv_\b__\bk_\be_\be_\bp
- and _\be_\bn_\bv_\b__\bc_\bh_\be_\bc_\bk.
+ the program being run. Entries in this file should either
+ be of the form VARIABLE=value or export VARIABLE=value.
+ The value may optionally be surrounded by single or double
+ quotes. Variables in this file are subject to other s\bsu\bud\bdo\bo
+ environment settings such as _\be_\bn_\bv_\b__\bk_\be_\be_\bp and _\be_\bn_\bv_\b__\bc_\bh_\be_\bc_\bk.
exempt_group
Users in this group are exempt from password and PATH
once Only lecture the user the first time they run s\bsu\bud\bdo\bo.
+ If no value is specified, a value of _\bo_\bn_\bc_\be is implied.
+ Negating the option results in a value of _\bn_\be_\bv_\be_\br being used.
+ The default value is _\bo_\bn_\bc_\be.
+
-1.7.0 December 3, 2008 15
+1.7.4 July 21, 2010 18
SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- If no value is specified, a value of _\bo_\bn_\bc_\be is implied.
- Negating the option results in a value of _\bn_\be_\bv_\be_\br being used.
- The default value is _\bo_\bn_\bc_\be.
-
lecture_file
Path to a file containing an alternate s\bsu\bud\bdo\bo lecture that
will be used in place of the standard lecture if the named
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
+ _\be_\bx_\be_\bm_\bp_\bt_\b__\bg_\br_\bo_\bu_\bp option are not affected by _\bs_\be_\bc_\bu_\br_\be_\b__\bp_\ba_\bt_\bh. This
+ option is not set by default.
+ syslog Syslog facility if syslog is being used for logging (negate
-1.7.0 December 3, 2008 16
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-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- _\be_\bx_\be_\bm_\bp_\bt_\b__\bg_\br_\bo_\bu_\bp option are not affected by _\bs_\be_\bc_\bu_\br_\be_\b__\bp_\ba_\bt_\bh. This
- is not set by default.
- syslog Syslog facility if syslog is being used for logging (negate
- to disable syslog logging). Defaults to local2.
+ to disable syslog logging). Defaults to auth.
verifypw This option controls when a password will be required when
a user runs s\bsu\bud\bdo\bo with the -\b-v\bv option. It has the following
is run by root with the _\b-_\bV option.
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 =, +=, -=, and !
- operators respectively. The default list of
- environment variables to remove is displayed when s\bsu\bud\bdo\bo
- is run by root with the _\b-_\bV option. Note that many
- operating systems will remove potentially dangerous
+ environment when the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt 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 =, +=, -=, and ! operators respectively. The
+ default list of environment variables to remove is
+ displayed when s\bsu\bud\bdo\bo is run by root with the _\b-_\bV option.
+ Note that many operating systems will remove
+ potentially dangerous variables from the environment of
+ any setuid process (such as s\bsu\bud\bdo\bo).
+ env_keep Environment variables to be preserved in the user's
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-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
- variables from the environment of any setuid process
- (such as s\bsu\bud\bdo\bo).
- env_keep Environment variables to be preserved in the user's
environment when the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt option is in effect.
This allows fine-grained control over the environment
s\bsu\bud\bdo\bo-spawned processes will receive. The argument may
_\b/_\be_\bt_\bc_\b/_\bn_\be_\bt_\bg_\br_\bo_\bu_\bp List of network groups
+ _\b/_\bv_\ba_\br_\b/_\bl_\bo_\bg_\b/_\bs_\bu_\bd_\bo_\b-_\bi_\bo I/O log files
+
E\bEX\bXA\bAM\bMP\bPL\bLE\bES\bS
Below are example _\bs_\bu_\bd_\bo_\be_\br_\bs entries. Admittedly, some of these are a bit
- contrived. First, we define our _\ba_\bl_\bi_\ba_\bs_\be_\bs:
+ contrived. First, we allow a few environment variables to pass and
+ then define our _\ba_\bl_\bi_\ba_\bs_\be_\bs:
+
+ # 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 :\
Host_Alias CUNETS = 128.138.0.0/255.255.0.0
Host_Alias CSNETS = 128.138.243.0, 128.138.204.0/24, 128.138.242.0
Host_Alias SERVERS = master, mail, www, ns
- Host_Alias CDROM = orion, perseus, hercules
-
- # Cmnd alias specification
- Cmnd_Alias DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\
- /usr/sbin/restore, /usr/sbin/rrestore
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+ Host_Alias CDROM = orion, perseus, hercules
+
+ # Cmnd alias specification
+ Cmnd_Alias DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\
+ /usr/sbin/restore, /usr/sbin/rrestore
Cmnd_Alias KILL = /usr/bin/kill
Cmnd_Alias PRINTING = /usr/sbin/lpc, /usr/bin/lprm
Cmnd_Alias SHUTDOWN = /usr/sbin/shutdown
any host but they must authenticate themselves first (since the entry
lacks the NOPASSWD tag).
- jack CSNETS = ALL
-
- The user j\bja\bac\bck\bk may run any command on the machines in the _\bC_\bS_\bN_\bE_\bT_\bS alias
- (the networks 128.138.243.0, 128.138.204.0, and 128.138.242.0). Of
-
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+ jack CSNETS = ALL
+
+ The user j\bja\bac\bck\bk may run any command on the machines in the _\bC_\bS_\bN_\bE_\bT_\bS alias
+ (the networks 128.138.243.0, 128.138.204.0, and 128.138.242.0). Of
those networks, only 128.138.204.0 has an explicit netmask (in CIDR
notation) indicating it is a class C network. For the other networks
in _\bC_\bS_\bN_\bE_\bT_\bS, the local machine's netmask will be used during matching.
pete HPPA = /usr/bin/passwd [A-Za-z]*, !/usr/bin/passwd root
+ %opers ALL = (: ADMINGRP) /usr/sbin/
+
+ Users in the o\bop\bpe\ber\brs\bs group may run commands in _\b/_\bu_\bs_\br_\b/_\bs_\bb_\bi_\bn_\b/ as themselves
+ with any group in the _\bA_\bD_\bM_\bI_\bN_\bG_\bR_\bP Runas_Alias (the a\bad\bdm\bm and o\bop\bpe\ber\br groups).
+
The user p\bpe\bet\bte\be is allowed to change anyone's password except for root on
the _\bH_\bP_\bP_\bA machines. Note that this assumes _\bp_\ba_\bs_\bs_\bw_\bd(1) does not take
- multiple usernames on the command line.
+ multiple user names on the command line.
bob SPARC = (OP) ALL : SGI = (OP) ALL
fred ALL = (DB) NOPASSWD: ALL
- The user f\bfr\bre\bed\bd can run commands as any user in the _\bD_\bB Runas_Alias
- (o\bor\bra\bac\bcl\ble\be or s\bsy\byb\bba\bas\bse\be) without giving a password.
- john ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root*
- On the _\bA_\bL_\bP_\bH_\bA machines, user j\bjo\boh\bhn\bn may su to anyone except root but he is
- not allowed to specify any options to the _\bs_\bu(1) command.
- jen ALL, !SERVERS = ALL
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+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+ The user f\bfr\bre\bed\bd can run commands as any user in the _\bD_\bB Runas_Alias
+ (o\bor\bra\bac\bcl\ble\be or s\bsy\byb\bba\bas\bse\be) without giving a password.
-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+ john ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root*
+ On the _\bA_\bL_\bP_\bH_\bA machines, user j\bjo\boh\bhn\bn may su to anyone except root but he is
+ not allowed to specify any options to the _\bs_\bu(1) command.
+
+ jen ALL, !SERVERS = ALL
The user j\bje\ben\bn may run any command on any machine except for those in the
_\bS_\bE_\bR_\bV_\bE_\bR_\bS Host_Alias (master, mail, www and ns).
Doesn't really prevent b\bbi\bil\bll\bl from running the commands listed in _\bS_\bU or
_\bS_\bH_\bE_\bL_\bL_\bS 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).
-
-P\bPR\bRE\bEV\bVE\bEN\bNT\bTI\bIN\bNG\bG S\bSH\bHE\bEL\bLL\bL E\bES\bSC\bCA\bAP\bPE\bES\bS
- Once s\bsu\bud\bdo\bo 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 s\bsu\bud\bdo\bo's access control and logging. Common programs
- that permit shell escapes include shells (obviously), editors,
- paginators, mail and terminal programs.
-1.7.0 December 3, 2008 21
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+ kind of restrictions should be considered advisory at best (and
+ reinforced by policy).
+
+ Furthermore, if the _\bf_\ba_\bs_\bt_\b__\bg_\bl_\bo_\bb 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 _\bf_\bn_\bm_\ba_\bt_\bc_\bh(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 _\bs_\bu_\bd_\bo_\be_\br_\bs 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 j\bjo\boh\bhn\bn can still run /usr/bin/passwd root if _\bf_\ba_\bs_\bt_\b__\bg_\bl_\bo_\bb is enabled by
+ changing to _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn and running ./passwd root instead.
+
+P\bPR\bRE\bEV\bVE\bEN\bNT\bTI\bIN\bNG\bG S\bSH\bHE\bEL\bLL\bL E\bES\bSC\bCA\bAP\bPE\bES\bS
+ Once s\bsu\bud\bdo\bo 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 s\bsu\bud\bdo\bo'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:
restrict Avoid giving users access to commands that allow the user to
File containing dummy exec functions:
+
+
+
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+SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
+
+
then s\bsu\bud\bdo\bo 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
Note that restricting shell escapes is not a panacea. Programs running
as root are still capable of many potentially hazardous operations
-
-
-
-1.7.0 December 3, 2008 22
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-SUDOERS(4) MAINTENANCE COMMANDS SUDOERS(4)
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(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 s\bsu\bud\bdo\boe\bed\bdi\bit\bt.
S\bSE\bEE\bE A\bAL\bLS\bSO\bO
- _\br_\bs_\bh(1), _\bs_\bu(1), _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3), _\bs_\bu_\bd_\bo(1m), _\bv_\bi_\bs_\bu_\bd_\bo(8)
+ _\br_\bs_\bh(1), _\bs_\bu(1), _\bf_\bn_\bm_\ba_\bt_\bc_\bh(3), _\bg_\bl_\bo_\bb(3), _\bs_\bu_\bd_\bo(1m), _\bv_\bi_\bs_\bu_\bd_\bo(8)
C\bCA\bAV\bVE\bEA\bAT\bTS\bS
The _\bs_\bu_\bd_\bo_\be_\br_\bs file should a\bal\blw\bwa\bay\bys\bs be edited by the v\bvi\bis\bsu\bud\bdo\bo command which
syntactically incorrect _\bs_\bu_\bd_\bo_\be_\br_\bs 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 as
+ 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 hostname command or use the _\bf_\bq_\bd_\bn option in _\bs_\bu_\bd_\bo_\be_\br_\bs.
B\bBU\bUG\bGS\bS
http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
the archives.
+
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D\bDI\bIS\bSC\bCL\bLA\bAI\bIM\bME\bER\bR
s\bsu\bud\bdo\bo is provided ``AS IS'' and any express or implied warranties,
including, but not limited to, the implied warranties of
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projects / debian / sudo / blobdiff