Imported Upstream version 1.6.9p10

[debian/sudo] / sudoers.cat

SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


N\bNA\bAM\bME\bE
       sudoers - list of which users may execute what

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
       The _\bs_\bu_\bd_\bo_\be_\br_\bs file is composed of two types of entries:
       aliases (basically variables) and user specifications
       (which specify who may run what).

       When multiple entries match for a user, they are applied
       in order.  Where there are multiple matches, the last
       match is used (which is not necessarily the most specific
       match).

       The _\bs_\bu_\bd_\bo_\be_\br_\bs grammar will be described below in Extended
       Backus-Naur Form (EBNF).  Don't despair if you don't know
       what EBNF is; it is fairly simple, and the definitions
       below are annotated.

       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_\b­
       _\bt_\bi_\bo_\bn _\br_\bu_\bl_\be_\bs.  E.g.,

        symbol ::= definition | alternate1 | alternate2 ...

       Each _\bp_\br_\bo_\bd_\bu_\bc_\bt_\bi_\bo_\bn _\br_\bu_\bl_\be references others and thus makes up a
       grammar for the language.  EBNF also contains the follow­
       ing operators, which many readers will recognize from reg­
       ular expressions.  Do not, however, confuse them with
       "wildcard" characters, which have different meanings.

       ?   Means that the preceding symbol (or group of symbols)
           is optional.  That is, it may appear once or not at
           all.

       *   Means that the preceding symbol (or group of symbols)
           may appear zero or more times.

       +   Means that the preceding symbol (or group of symbols)
           may appear one or more times.

       Parentheses may be used to group symbols together.  For
       clarity, we 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

       There are four kinds of aliases: User_Alias, Runas_Alias,
       Host_Alias and Cmnd_Alias.






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        Alias ::= 'User_Alias'  User_Alias (':' User_Alias)* |
                  'Runas_Alias' Runas_Alias (':' Runas_Alias)* |
                  'Host_Alias'  Host_Alias (':' Host_Alias)* |
                  'Cmnd_Alias'  Cmnd_Alias (':' Cmnd_Alias)*

        User_Alias ::= NAME '=' User_List

        Runas_Alias ::= NAME '=' Runas_List

        Host_Alias ::= NAME '=' Host_List

        Cmnd_Alias ::= NAME '=' Cmnd_List

        NAME ::= [A-Z]([A-Z][0-9]_)*

       Each _\ba_\bl_\bi_\ba_\bs definition is of the form

        Alias_Type NAME = item1, item2, ...

       where _\bA_\bl_\bi_\ba_\bs_\b__\bT_\by_\bp_\be is one of User_Alias, Runas_Alias,
       Host_Alias, or Cmnd_Alias.  A NAME is a string of upper­
       case letters, numbers, and underscore characters ('_').  A
       NAME m\bmu\bus\bst\bt 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.,

        Alias_Type NAME = item1, item2, item3 : NAME = item4, item5

       The definitions of what constitutes a valid _\ba_\bl_\bi_\ba_\bs member
       follow.

        User_List ::= User |
                      User ',' User_List

        User ::= '!'* username |
                 '!'* '%'group |
                 '!'* '+'netgroup |
                 '!'* User_Alias

       A User_List 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.

        Runas_List ::= Runas_User |
                       Runas_User ',' Runas_List

        Runas_User ::= '!'* username |
                       '!'* '#'uid |
                       '!'* '%'group |
                       '!'* +netgroup |
                       '!'* Runas_Alias



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       A Runas_List is similar to a User_List except that it can
       also contain uids (prefixed with '#') and 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 con­
       sidered 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 |
                 '!'* ip_addr |
                 '!'* network(/netmask)? |
                 '!'* '+'netgroup |
                 '!'* Host_Alias

       A Host_List is made up of one or more hostnames, 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 of the local host's network interfaces and, if the
       network number corresponds to one of the hosts's network
       interfaces, the corresponding netmask will be used.  The
       netmask may be specified either in standard IP address
       notation (e.g. 255.255.255.0 or ffff:ffff:ffff:ffff::), or
       CIDR notation (number of bits, e.g. 24 or 64).  A hostname
       may include shell-style wildcards (see the Wildcards sec­
       tion 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.

        Cmnd_List ::= Cmnd |
                      Cmnd ',' Cmnd_List

        commandname ::= filename |
                        filename args |
                        filename '""'

        Cmnd ::= '!'* commandname |
                 '!'* directory |
                 '!'* "sudoedit" |
                 '!'* Cmnd_Alias

       A Cmnd_List is a list of one or more commandnames, direc­
       tories, and other aliases.  A commandname is a fully qual­
       ified filename which may include 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 "" to indicate that the command may only be run



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       w\bwi\bit\bth\bho\bou\but\bt command line arguments.  A directory is a fully
       qualified pathname 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).

       If a Cmnd has associated command line arguments, then the
       arguments in the Cmnd must match exactly those given by
       the user on the command line (or match the wildcards if
       there are any).  Note that the following characters must
       be escaped with a '\' if they are used in command argu­
       ments: ',', ':', '=', '\'.  The special command "sudoedit"
       is used to permit a user to run s\bsu\bud\bdo\bo with the -\b-e\be flag (or
       as s\bsu\bud\bdo\boe\bed\bdi\bit\bt).  It may take command line arguments just as
       a normal command does.

       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, or commands being run
       as a specific user.

        Default_Type ::= 'Defaults' |
                         'Defaults' '@' Host_List |
                         'Defaults' ':' User_List |
                         'Defaults' '>' Runas_List

        Default_Entry ::= Default_Type Parameter_List

        Parameter_List ::= Parameter |
                           Parameter ',' Parameter_List

        Parameter ::= Parameter '=' Value |
                      Parameter '+=' Value |
                      Parameter '-=' Value |
                      '!'* Parameter

       Parameters may be f\bfl\bla\bag\bgs\bs, i\bin\bnt\bte\beg\bge\ber\br values, s\bst\btr\bri\bin\bng\bgs\bs, or
       l\bli\bis\bst\bts\bs.  Flags are implicitly boolean and can be turned off
       via the '!'  operator.  Some integer, string and list
       parameters may also be used in a boolean context to dis­
       able them.  Values may be enclosed in double quotes (")
       when they contain multiple words.  Special characters may
       be escaped with a backslash (\).

       Lists have two additional assignment operators, += and -=.
       These operators are used to add to and delete from a list
       respectively.  It is not an error to use the -= operator
       to remove an element that does not exist in a list.

       See "SUDOERS OPTIONS" for a list of supported Defaults
       parameters.



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       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

        Cmnd_Spec ::= Runas_Spec? Tag_Spec* Cmnd

        Runas_Spec ::= '(' Runas_List ')'

        Tag_Spec ::= ('NOPASSWD:' | 'PASSWD:' | 'NOEXEC:' | 'EXEC:' |
                      'SETENV:' | 'NOSETENV:')

       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

       A Runas_Spec is simply a Runas_List (as defined above)
       enclosed in a set of parentheses.  If you do not specify a
       Runas_Spec in the user specification, a default Runas_Spec
       of r\bro\boo\bot\bt will be used.  A Runas_Spec sets the default for
       commands that follow it.  What this means is that for the
       entry:

        dgb    boulder = (operator) /bin/ls, /bin/kill, /usr/bin/lprm

       The user d\bdg\bgb\bb may run _\b/_\bb_\bi_\bn_\b/_\bl_\bs, _\b/_\bb_\bi_\bn_\b/_\bk_\bi_\bl_\bl, and _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bl_\bp_\br_\bm
       -- but only as o\bop\bpe\ber\bra\bat\bto\bor\br.  E.g.,

        $ sudo -u operator /bin/ls.

       It is also possible to override a Runas_Spec later on in
       an entry.  If we modify the entry like so:

        dgb    boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm

       Then user d\bdg\bgb\bb is now allowed to run _\b/_\bb_\bi_\bn_\b/_\bl_\bs as o\bop\bpe\ber\bra\bat\bto\bor\br,
       but  _\b/_\bb_\bi_\bn_\b/_\bk_\bi_\bl_\bl and _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bl_\bp_\br_\bm as r\bro\boo\bot\bt.

       T\bTa\bag\bg_\b_S\bSp\bpe\bec\bc

       A command may have zero or more tags associated with it.
       There are six 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).



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       _\bN_\bO_\bP_\bA_\bS_\bS_\bW_\bD _\ba_\bn_\bd _\bP_\bA_\bS_\bS_\bW_\bD

       By default, s\bsu\bud\bdo\bo requires that a user authenticate him or
       herself before running a command.  This behavior can be
       modified via the NOPASSWD tag.  Like a Runas_Spec, the
       NOPASSWD tag sets a default for the commands that follow
       it in the Cmnd_Spec_List.  Conversely, the PASSWD tag can
       be used to reverse things.  For example:

        ray    rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm

       would allow the user r\bra\bay\by to run _\b/_\bb_\bi_\bn_\b/_\bk_\bi_\bl_\bl, _\b/_\bb_\bi_\bn_\b/_\bl_\bs, and
       _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bl_\bp_\br_\bm as root on the machine rushmore as r\bro\boo\bot\bt
       without authenticating himself.  If we only want r\bra\bay\by to be
       able to run _\b/_\bb_\bi_\bn_\b/_\bk_\bi_\bl_\bl without a password the entry would
       be:

        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 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 user on the current host, he or she will be
       able to run sudo -l without a password.  Additionally, a
       user may only run sudo -v without a password if the
       NOPASSWD tag is present for all a user's entries that per­
       tain to the current host.  This behavior may be overridden
       via the verifypw and listpw options.

       _\bN_\bO_\bE_\bX_\bE_\bC _\ba_\bn_\bd _\bE_\bX_\bE_\bC

       If s\bsu\bud\bdo\bo has been compiled with _\bn_\bo_\be_\bx_\be_\bc support and the
       underlying operating system supports it, the NOEXEC tag
       can be used to prevent a dynamically-linked executable
       from running further commands itself.

       In the following example, user a\baa\bar\bro\bon\bn may run _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bm_\bo_\br_\be
       and _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bv_\bi but shell escapes will be disabled.

        aaron  shanty = NOEXEC: /usr/bin/more, /usr/bin/vi

       See the "PREVENTING SHELL ESCAPES" section below for more
       details on how NOEXEC works and whether or not it will
       work on your system.

       _\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.



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       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.

       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 char­
       acters) to be used in pathnames as well as 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.

       [...]   Matches any character in the specified range.

       [!...]  Matches any character n\bno\bot\bt in the specified range.

       \x      For any character "x", evaluates to "x".  This is
               used to escape special characters such as: "*",
               "?", "[", and "}".

       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 slash d\bdo\boe\bes\bs get matched by wild­
       cards.  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

       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 com­
               mand is not allowed to be run with a\ban\bny\by arguments.

       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 as a uid).  Both the
       comment character and any text after it, up to the end of
       the line, are ignored.

       The reserved word A\bAL\bLL\bL is a built-in _\ba_\bl_\bi_\ba_\bs that always
       causes a match to succeed.  It can be used wherever one
       might otherwise use a Cmnd_Alias, User_Alias, Runas_Alias,
       or Host_Alias.  You should not try to define your own



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       _\ba_\bl_\bi_\ba_\bs called A\bAL\bLL\bL as the built-in alias will be used in
       preference to your own.  Please note that using A\bAL\bLL\bL can be
       dangerous since in a command context, it allows the user
       to run a\ban\bny\by command on the system.

       An exclamation point ('!') can be used as a logical _\bn_\bo_\bt
       operator both in an _\ba_\bl_\bi_\ba_\bs and in front of a Cmnd.  This
       allows one to exclude certain values.  Note, however, that
       using a ! in conjunction with the built-in ALL alias to
       allow a user to run "all but a few" commands rarely works
       as intended (see SECURITY NOTES below).

       Long lines can be continued with a backslash ('\') as the
       last character on the line.

       Whitespace between elements in a list as well as special
       syntactic characters in a _\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): '@', '!', '=', ':', ',', '(', ')', '\'.

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:

       always_set_home If set, s\bsu\bud\bdo\bo will set the HOME environment
                       variable to the home directory of the tar­
                       get user (which is root unless the -\b-u\bu
                       option is used).  This effectively means
                       that the -\b-H\bH flag is always implied.  This
                       flag is _\bo_\bf_\bf by default.

       authenticate    If set, users must authenticate themselves
                       via a password (or other means of authen­
                       tication) before they may run commands.
                       This default may be overridden via the
                       PASSWD and NOPASSWD tags.  This flag is _\bo_\bn
                       by default.

       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 secu­
                       rity hole as it allows the user to run any
                       arbitrary command as root without logging.
                       A safer alternative is to place a colon-
                       separated list of editors in the editor
                       variable.  v\bvi\bis\bsu\bud\bdo\bo will then only use the
                       EDITOR or VISUAL if they match a value



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                       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_* 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 env_check lists are displayed
                       when s\bsu\bud\bdo\bo is run by root with the _\b-_\bV
                       option.  If s\bsu\bud\bdo\bo was compiled with the
                       SECURE_PATH option, 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 work­
                       ing (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 perfor­
                       mance 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 quali­
                       fied 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 '' (cur­
                       rent dir) in the PATH environment vari­
                       able; the PATH itself is not modified.
                       This flag is _\bo_\bf_\bf by default.  Currently,
                       while it is possible to set _\bi_\bg_\bn_\bo_\br_\be_\b__\bd_\bo_\bt in
                       _\bs_\bu_\bd_\bo_\be_\br_\bs, its value is not used.  This
                       option should be considered read-only (it
                       will be fixed in a future version of
                       s\bsu\bud\bdo\bo).

       ignore_local_sudoers
                       If set via LDAP, parsing of
                       @sysconfdir@/sudoers will be skipped.
                       This is intended for Enterprises that wish
                       to prevent the usage of local sudoers
                       files so that only LDAP is used.  This
                       thwarts the efforts of rogue operators who
                       would attempt to add roles to



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                       @sysconfdir@/sudoers.  When this option is
                       present, @sysconfdir@/sudoers does not
                       even need to exist.  Since this option
                       tells s\bsu\bud\bdo\bo how to behave when no specific
                       LDAP entries have been matched, this
                       sudoOption is only meaningful for the
                       cn=defaults section.  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_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.

       long_otp_prompt When validating with a One Time Password
                       (OPT) scheme such as S\bS/\b/K\bKe\bey\by or O\bOP\bPI\bIE\bE, 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 _\bo_\bf_\bf by default.

       mail_always     Send mail to the _\bm_\ba_\bi_\bl_\bt_\bo user every time a
                       users runs s\bsu\bud\bdo\bo.  This flag is _\bo_\bf_\bf by
                       default.

       mail_badpass    Send mail to the _\bm_\ba_\bi_\bl_\bt_\bo user if the user
                       running s\bsu\bud\bdo\bo does not enter the correct
                       password.  This flag is _\bo_\bf_\bf by default.

       mail_no_host    If set, mail will be sent to the _\bm_\ba_\bi_\bl_\bt_\bo
                       user if the invoking user exists in the
                       _\bs_\bu_\bd_\bo_\be_\br_\bs file, but is not allowed to run
                       commands on the current host.  This flag
                       is _\bo_\bf_\bf by default.

       mail_no_perms   If set, mail will be sent to the _\bm_\ba_\bi_\bl_\bt_\bo
                       user if the invoking user is allowed to
                       use s\bsu\bud\bdo\bo but the command they are trying
                       is not listed in their _\bs_\bu_\bd_\bo_\be_\br_\bs file entry
                       or is explicitly denied.  This flag is _\bo_\bf_\bf
                       by default.

       mail_no_user    If set, mail will be sent to the _\bm_\ba_\bi_\bl_\bt_\bo
                       user if the invoking user is not in the
                       _\bs_\bu_\bd_\bo_\be_\br_\bs file.  This flag is _\bo_\bn by default.




1.6.9p10                December 17, 2007                      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
                       well as the "PREVENTING SHELL ESCAPES"
                       section at the end of this manual.  This
                       flag is _\bo_\bf_\bf by default.

       path_info       Normally, s\bsu\bud\bdo\bo will tell the user when a
                       command could not be found in their PATH
                       environment variable.  Some sites may wish
                       to disable this as it could be used to
                       gather information on the location of exe­
                       cutables that the normal user does not
                       have access to.  The disadvantage is that
                       if the executable is simply not in the
                       user's PATH, s\bsu\bud\bdo\bo will tell the user that
                       they are not allowed to run it, which can
                       be confusing.  This flag is _\bo_\bn by default.

       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 "Pass­
                       word:".  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 _\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.

       requiretty      If set, s\bsu\bud\bdo\bo will only run when the user
                       is logged in to a real tty.  This will
                       disallow things like "rsh somehost sudo
                       ls" since _\br_\bs_\bh(1) does not allocate a tty.
                       Because it is not possible to turn off
                       echo when there is no tty present, some
                       sites may wish to set this flag to prevent
                       a user from entering a visible password.
                       This flag is _\bo_\bf_\bf by default.

       root_sudo       If set, root is allowed to run s\bsu\bud\bdo\bo too.
                       Disabling this prevents users from "chain­
                       ing" 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.  Disabling _\br_\bo_\bo_\bt_\b__\bs_\bu_\bd_\bo provides no



1.6.9p10                December 17, 2007                      11





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


                       real additional security; it exists purely
                       for historical reasons.  This flag is _\bo_\bn
                       by default.

       rootpw          If set, s\bsu\bud\bdo\bo will prompt for the root
                       password instead of the password of the
                       invoking user.  This flag is _\bo_\bf_\bf by
                       default.

       runaspw         If set, s\bsu\bud\bdo\bo will prompt for the password
                       of the user defined by the _\br_\bu_\bn_\ba_\bs_\b__\bd_\be_\bf_\ba_\bu_\bl_\bt
                       option (defaults to root) instead of the
                       password of the invoking user.  This flag
                       is _\bo_\bf_\bf by default.

       set_home        If set and s\bsu\bud\bdo\bo is invoked with the -\b-s\bs
                       flag 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
                       flag 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 flag is given).  However,
                       since some programs (including the RCS
                       revision control system) use LOGNAME to
                       determine the real identity of the user,
                       it may be desirable to change this behav­
                       ior.  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.

       setenv          Allow the user to disable the _\be_\bn_\bv_\b__\br_\be_\bs_\be_\bt
                       option from the command line.  Addition­
                       ally, environment variables set via the
                       command line 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.  This flag is
                       _\bo_\bf_\bf by default.

       shell_noargs    If set and s\bsu\bud\bdo\bo is invoked with no argu­
                       ments it acts as if the -\b-s\bs flag had been
                       given.  That is, it runs a shell as root
                       (the shell is determined by the SHELL
                       environment variable if it is set, falling
                       back on the shell listed in the invoking



1.6.9p10                December 17, 2007                      12





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


                       user's /etc/passwd entry if not).  This
                       flag is _\bo_\bf_\bf by default.

       stay_setuid     Normally, when s\bsu\bud\bdo\bo executes a command the
                       real and effective UIDs are set to the
                       target user (root by default).  This
                       option changes that behavior such that the
                       real UID is left as the invoking user's
                       UID.  In other words, this makes s\bsu\bud\bdo\bo act
                       as a setuid wrapper.  This can be useful
                       on systems that disable some potentially
                       dangerous functionality when a program is
                       run setuid.  This option is only effective
                       on systems with either the _\bs_\be_\bt_\br_\be_\bu_\bi_\bd_\b(_\b) or
                       _\bs_\be_\bt_\br_\be_\bs_\bu_\bi_\bd_\b(_\b) function.  This flag is _\bo_\bf_\bf by
                       default.

       targetpw        If set, s\bsu\bud\bdo\bo will prompt for the password
                       of the user specified by the -\b-u\bu flag
                       (defaults to root) instead of the password
                       of the invoking user.  Note that this pre­
                       cludes the use of a uid not listed in the
                       passwd database as an argument to the -\b-u\bu
                       flag.  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 direc­
                       tory 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 user is logged in on in that
                       directory.  This flag is _\bo_\bf_\bf by default.

       use_loginclass  If set, s\bsu\bud\bdo\bo will apply the defaults spec­
                       ified 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.

       I\bIn\bnt\bte\beg\bge\ber\brs\bs:

       passwd_tries    The number of tries a user gets to enter
                       his/her password before s\bsu\bud\bdo\bo logs the
                       failure and exits.  The default is 3.

       I\bIn\bnt\bte\beg\bge\ber\brs\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:

       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 80 (use 0 or
                       negate the option to disable word wrap).




1.6.9p10                December 17, 2007                      13





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


       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.

       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 times­
                       tamps via sudo -v and sudo -k respec­
                       tively.

       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
                       0022.

       S\bSt\btr\bri\bin\bng\bgs\bs:

       badpass_message Message that is displayed if a user enters
                       an incorrect password.  The default is
                       Sorry, try again. unless insults are
                       enabled.

       editor          A colon (':') separated list of editors
                       allowed to be 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 pos­
                       sible, or the first editor in the list
                       that exists and is executable.  The
                       default is the path to vi on your system.

       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 ***.

       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_\b­
                       _\be_\bc_\bv_\be_\b(_\b) library functions that just return
                       an error.  This is used to implement the
                       _\bn_\bo_\be_\bx_\be_\bc functionality on systems that sup­
                       port LD_PRELOAD or its equivalent.
                       Defaults to
                       _\b/_\bu_\bs_\br_\b/_\bl_\bo_\bc_\ba_\bl_\b/_\bl_\bi_\bb_\be_\bx_\be_\bc_\b/_\bs_\bu_\bd_\bo_\b__\bn_\bo_\be_\bx_\be_\bc_\b._\bs_\bo.

       passprompt      The default prompt to use when asking for
                       a password; can be overridden via the -\b-p\bp
                       option or the SUDO_PROMPT environment
                       variable.  The following percent (`%')
                       escapes are supported:



1.6.9p10                December 17, 2007                      14





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


                       %H  expanded to the local hostname includ­
                           ing the domain name (on if the
                           machine's hostname is fully qualified
                           or the _\bf_\bq_\bd_\bn option is set)

                       %h  expanded to the local hostname without
                           the domain name

                       %U  expanded to the login name of the user
                           the command will be run as (defaults
                           to root)

                       %u  expanded to the invoking user's login
                           name

                       %%  two consecutive % characters are col­
                           lapsed into a single % character

                       The default value is Password:.

       runas_default   The default user to run commands as if the
                       -\b-u\bu flag is not specified on the command
                       line.  This defaults to root.  Note that
                       if _\br_\bu_\bn_\ba_\bs_\b__\bd_\be_\bf_\ba_\bu_\bl_\bt is set it m\bmu\bus\bst\bt occur
                       before any Runas_Alias specifications.

       syslog_badpri   Syslog priority to use when user authenti­
                       cates unsuccessfully.  Defaults to alert.

       syslog_goodpri  Syslog priority to use when user authenti­
                       cates successfully.  Defaults to notice.

       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.

       timestampowner  The owner of the timestamp directory and
                       the timestamps stored therein.  The
                       default is root.

       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:

       exempt_group
                   Users in this group are exempt from password
                   and PATH requirements.  This is not set by
                   default.

       lecture     This option controls when a short lecture will
                   be printed along with the password prompt.  It
                   has the following possible values:

                   always  Always lecture the user.

                   never   Never lecture the user.



1.6.9p10                December 17, 2007                      15





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


                   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.

       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 file exists.  By
                   default, s\bsu\bud\bdo\bo uses a built-in lecture.

       listpw      This option controls when a password will be
                   required when a user runs s\bsu\bud\bdo\bo with the -\b-l\bl
                   flag.  It has the following possible values:

                   all     All the user's _\bs_\bu_\bd_\bo_\be_\br_\bs entries for the
                           current host must have the NOPASSWD
                           flag set to avoid entering a password.

                   always  The user must always enter a password
                           to use the -\b-l\bl flag.

                   any     At least one of the user's _\bs_\bu_\bd_\bo_\be_\br_\bs
                           entries for the current host must have
                           the NOPASSWD flag set to avoid enter­
                           ing a password.

                   never   The user need never enter a password
                           to use the -\b-l\bl flag.

                   If no value is specified, a value of _\ba_\bn_\by is
                   implied.  Negating the option results in a
                   value of _\bn_\be_\bv_\be_\br being used.  The default value
                   is _\ba_\bn_\by.

       logfile     Path to the s\bsu\bud\bdo\bo log file (not the syslog log
                   file).  Setting a path turns on logging to a
                   file; negating this option turns it off.  By
                   default, s\bsu\bud\bdo\bo logs via syslog.

       mailerflags Flags to use when invoking mailer. Defaults to
                   -\b-t\bt.

       mailerpath  Path to mail program used to send warning
                   mail.  Defaults to the path to sendmail found
                   at configure time.

       mailto      Address to send warning and error mail to.
                   The address should be enclosed in double
                   quotes (") to protect against s\bsu\bud\bdo\bo interpret­
                   ing the @ sign.  Defaults to root.



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SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


       syslog      Syslog facility if syslog is being used for
                   logging (negate to disable syslog logging).
                   Defaults to local2.

       verifypw    This option controls when a password will be
                   required when a user runs s\bsu\bud\bdo\bo with the -\b-v\bv
                   flag.  It has the following possible values:

                   all     All the user's _\bs_\bu_\bd_\bo_\be_\br_\bs entries for the
                           current host must have the NOPASSWD
                           flag set to avoid entering a password.

                   always  The user must always enter a password
                           to use the -\b-v\bv flag.

                   any     At least one of the user's _\bs_\bu_\bd_\bo_\be_\br_\bs
                           entries for the current host must have
                           the NOPASSWD flag set to avoid enter­
                           ing a password.

                   never   The user need never enter a password
                           to use the -\b-v\bv flag.

                   If no value is specified, a value of _\ba_\bl_\bl is
                   implied.  Negating the option results in a
                   value of _\bn_\be_\bv_\be_\br being used.  The default value
                   is _\ba_\bl_\bl.

       L\bLi\bis\bst\bts\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:

       env_check       Environment variables to be removed from
                       the user's environment if the variable's
                       value contains % or / characters.  This
                       can be used to guard against printf-style
                       format vulnerabilities in poorly-written
                       programs.  The argument may be a dou­
                       ble-quoted, space-separated list or a sin­
                       gle value without double-quotes.  The list
                       can be replaced, added to, deleted from,
                       or disabled by using the =, +=, -=, and !
                       operators respectively.  Regardless of
                       whether the env_reset option is enabled or
                       disabled, variables specified by env_check
                       will be preserved in the environment if
                       they pass the aforementioned check.  The
                       default list of environment variables to
                       check is displayed when s\bsu\bud\bdo\bo 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,



1.6.9p10                December 17, 2007                      17





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


                       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 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 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 vari­
                       ables to keep is displayed when s\bsu\bud\bdo\bo is
                       run by root with the _\b-_\bV option.

       When logging via _\bs_\by_\bs_\bl_\bo_\bg(3), s\bsu\bud\bdo\bo accepts the following
       values for the syslog facility (the value of the s\bsy\bys\bsl\blo\bog\bg
       Parameter): a\bau\but\bth\bhp\bpr\bri\biv\bv (if your OS supports it), a\bau\but\bth\bh, d\bda\bae\be­\b­
       m\bmo\bon\bn, u\bus\bse\ber\br, l\blo\boc\bca\bal\bl0\b0, l\blo\boc\bca\bal\bl1\b1, l\blo\boc\bca\bal\bl2\b2, l\blo\boc\bca\bal\bl3\b3, l\blo\boc\bca\bal\bl4\b4, l\blo\boc\bca\bal\bl5\b5,
       l\blo\boc\bca\bal\bl6\b6, and l\blo\boc\bca\bal\bl7\b7.  The following syslog priorities are
       supported: a\bal\ble\ber\brt\bt, c\bcr\bri\bit\bt, d\bde\beb\bbu\bug\bg, e\bem\bme\ber\brg\bg, e\ber\brr\br, i\bin\bnf\bfo\bo, n\bno\bot\bti\bic\bce\be,
       and w\bwa\bar\brn\bni\bin\bng\bg.

F\bFI\bIL\bLE\bES\bS
       _\b/_\be_\bt_\bc_\b/_\bs_\bu_\bd_\bo_\be_\br_\bs         List of who can run what
       _\b/_\be_\bt_\bc_\b/_\bg_\br_\bo_\bu_\bp           Local groups file
       _\b/_\be_\bt_\bc_\b/_\bn_\be_\bt_\bg_\br_\bo_\bu_\bp        List of network groups

E\bEX\bXA\bAM\bMP\bPL\bLE\bES\bS
       Since the _\bs_\bu_\bd_\bo_\be_\br_\bs file is parsed in a single pass, order
       is important.  In general, you should structure _\bs_\bu_\bd_\bo_\be_\br_\bs
       such that the Host_Alias, User_Alias, and Cmnd_Alias spec­
       ifications come first, followed by any Default_Entry
       lines, and finally the Runas_Alias and user specifica­
       tions.  The basic rule of thumb is you cannot reference an
       Alias that has not already been defined.

       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:

        # User alias specification
        User_Alias     FULLTIMERS = millert, mikef, dowdy
        User_Alias     PARTTIMERS = bostley, jwfox, crawl
        User_Alias     WEBMASTERS = will, wendy, wim





1.6.9p10                December 17, 2007                      18





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


        # Runas alias specification
        Runas_Alias    OP = root, operator
        Runas_Alias    DB = oracle, sybase

        # Host alias specification
        Host_Alias     SPARC = bigtime, eclipse, moet, anchor :\
                       SGI = grolsch, dandelion, black :\
                       ALPHA = widget, thalamus, foobar :\
                       HPPA = boa, nag, python
        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
        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
        Cmnd_Alias     REBOOT = /usr/sbin/reboot
        Cmnd_Alias     SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh, \
                                /usr/local/bin/tcsh, /usr/bin/rsh, \
                                /usr/local/bin/zsh
        Cmnd_Alias     SU = /usr/bin/su
        Cmnd_Alias     PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less

       Here we override some of the compiled in default values.
       We want s\bsu\bud\bdo\bo to log via _\bs_\by_\bs_\bl_\bo_\bg(3) using the _\ba_\bu_\bt_\bh facility
       in all cases.  We don't want to subject the full time
       staff to the s\bsu\bud\bdo\bo lecture, user m\bmi\bil\bll\ble\ber\brt\bt need not give a
       password, and we don't want to reset the LOGNAME, USER or
       USERNAME environment variables when running commands as
       root.  Additionally, on the machines in the _\bS_\bE_\bR_\bV_\bE_\bR_\bS
       Host_Alias, we keep an additional local log file and make
       sure we log the year in each log line since the log
       entries will be kept around for several years.  Lastly, we
       disable shell escapes for the commands in the PAGERS
       Cmnd_Alias (_\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bm_\bo_\br_\be, _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bp_\bg and _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bl_\be_\bs_\bs).

        # Override built-in defaults
        Defaults               syslog=auth
        Defaults>root          !set_logname
        Defaults:FULLTIMERS    !lecture
        Defaults:millert       !authenticate
        Defaults@SERVERS       log_year, logfile=/var/log/sudo.log
        Defaults!PAGERS        noexec

       The _\bU_\bs_\be_\br _\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc_\ba_\bt_\bi_\bo_\bn is the part that actually deter­
       mines who may run what.

        root           ALL = (ALL) ALL
        %wheel         ALL = (ALL) ALL



1.6.9p10                December 17, 2007                      19





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


       We let r\bro\boo\bot\bt and any user in group w\bwh\bhe\bee\bel\bl run any command on
       any host as any user.

        FULLTIMERS     ALL = NOPASSWD: ALL

       Full time sysadmins (m\bmi\bil\bll\ble\ber\brt\bt, m\bmi\bik\bke\bef\bf, and d\bdo\bow\bwd\bdy\by) may run
       any command on any host without authenticating themselves.

        PARTTIMERS     ALL = ALL

       Part time sysadmins (b\bbo\bos\bst\btl\ble\bey\by, j\bjw\bwf\bfo\box\bx, and c\bcr\bra\baw\bwl\bl) may run
       any command on any host but they must authenticate them­
       selves 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 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.

        lisa           CUNETS = ALL

       The user l\bli\bis\bsa\ba may run any command on any host in the
       _\bC_\bU_\bN_\bE_\bT_\bS alias (the class B network 128.138.0.0).

        operator       ALL = DUMPS, KILL, SHUTDOWN, HALT, REBOOT, PRINTING,\
                       sudoedit /etc/printcap, /usr/oper/bin/

       The o\bop\bpe\ber\bra\bat\bto\bor\br user may run commands limited to simple main­
       tenance.  Here, those are commands related to backups,
       killing processes, the printing system, shutting down the
       system, and any commands in the directory _\b/_\bu_\bs_\br_\b/_\bo_\bp_\be_\br_\b/_\bb_\bi_\bn_\b/.

        joe            ALL = /usr/bin/su operator

       The user j\bjo\boe\be may only _\bs_\bu(1) to operator.

        pete           HPPA = /usr/bin/passwd [A-z]*, !/usr/bin/passwd root

       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.

        bob            SPARC = (OP) ALL : SGI = (OP) ALL

       The user b\bbo\bob\bb may run anything on the _\bS_\bP_\bA_\bR_\bC and _\bS_\bG_\bI
       machines as any user listed in the _\bO_\bP Runas_Alias (r\bro\boo\bot\bt
       and o\bop\bpe\ber\bra\bat\bto\bor\br).

        jim            +biglab = ALL



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SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


       The user j\bji\bim\bm may run any command on machines in the _\bb_\bi_\bg_\bl_\ba_\bb
       netgroup.  s\bsu\bud\bdo\bo knows that "biglab" is a netgroup due to
       the '+' prefix.

        +secretaries   ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser

       Users in the s\bse\bec\bcr\bre\bet\bta\bar\bri\bie\bes\bs 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.

        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 give _\bs_\bu(1) any flags.

        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).

        jill           SERVERS = /usr/bin/, !SU, !SHELLS

       For any machine in the _\bS_\bE_\bR_\bV_\bE_\bR_\bS Host_Alias, j\bji\bil\bll\bl may run
       any commands in the directory _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/ except for those
       commands belonging to the _\bS_\bU and _\bS_\bH_\bE_\bL_\bL_\bS Cmnd_Aliases.

        steve          CSNETS = (operator) /usr/local/op_commands/

       The user s\bst\bte\bev\bve\be may run any command in the directory
       /usr/local/op_commands/ but only as user operator.

        matt           valkyrie = KILL

       On his personal workstation, valkyrie, m\bma\bat\btt\bt needs to be
       able to kill hung processes.

        WEBMASTERS     www = (www) ALL, (root) /usr/bin/su www

       On the host www, any user in the _\bW_\bE_\bB_\bM_\bA_\bS_\bT_\bE_\bR_\bS User_Alias
       (will, wendy, and wim), may run any command as user www
       (which owns the web pages) or simply _\bs_\bu(1) to www.

        ALL            CDROM = NOPASSWD: /sbin/umount /CDROM,\
                       /sbin/mount -o nosuid\,nodev /dev/cd0a /CDROM

       Any user may mount or unmount a CD-ROM on the machines in
       the CDROM Host_Alias (orion, perseus, hercules) without
       entering a password.  This is a bit tedious for users to



1.6.9p10                December 17, 2007                      21





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


       type, so it is a prime candidate for encapsulating in a
       shell script.

S\bSE\bEC\bCU\bUR\bRI\bIT\bTY\bY N\bNO\bOT\bTE\bES\bS
       It is generally not effective to "subtract" commands from
       ALL using the '!' operator.  A user can trivially circum­
       vent this by copying the desired command to a different
       name and then executing that.  For example:

           bill        ALL = ALL, !SU, !SHELLS

       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 com­
       mands 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.

       There are two basic approaches to this problem:

       restrict  Avoid giving users access to commands that allow
                 the user to run arbitrary commands.  Many edi­
                 tors have a restricted mode where shell escapes
                 are disabled, though s\bsu\bud\bdo\boe\bed\bdi\bit\bt is a better solu­
                 tion to running editors via s\bsu\bud\bdo\bo.  Due to the
                 large number of programs that offer shell
                 escapes, restricting users to the set of pro­
                 grams that do not if often unworkable.

       noexec    Many systems that support shared libraries have
                 the ability to override default library func­
                 tions by pointing an environment variable (usu­
                 ally LD_PRELOAD) to an alternate shared library.
                 On such systems, s\bsu\bud\bdo\bo's _\bn_\bo_\be_\bx_\be_\bc functionality can
                 be used to prevent a program run by s\bsu\bud\bdo\bo from
                 executing any other programs.  Note, however,
                 that this applies only to native dynamically-
                 linked executables.  Statically-linked executa­
                 bles and foreign executables running under
                 binary emulation are not affected.

                 To tell whether or not s\bsu\bud\bdo\bo supports _\bn_\bo_\be_\bx_\be_\bc, you
                 can run the following as root:

                     sudo -V | grep "dummy exec"



1.6.9p10                December 17, 2007                      22





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


                 If the resulting output contains a line that
                 begins with:

                     File containing dummy exec functions:

                 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 whether or not
                 _\bn_\bo_\be_\bx_\be_\bc will work at compile-time.  _\bn_\bo_\be_\bx_\be_\bc should
                 work on SunOS, Solaris, *BSD, Linux, IRIX, Tru64
                 UNIX, MacOS X, and HP-UX 11.x.  It is known n\bno\bot\bt
                 to work on AIX and UnixWare.  _\bn_\bo_\be_\bx_\be_\bc is expected
                 to work on most operating systems that support
                 the LD_PRELOAD environment variable.  Check your
                 operating system's manual pages for the dynamic
                 linker (usually ld.so, ld.so.1, dyld, dld.sl,
                 rld, or loader) to see if LD_PRELOAD is sup­
                 ported.

                 To enable _\bn_\bo_\be_\bx_\be_\bc for a command, use the NOEXEC
                 tag as documented in the User Specification sec­
                 tion above.  Here is that example again:

                  aaron  shanty = NOEXEC: /usr/bin/more, /usr/bin/vi

                 This allows user a\baa\bar\bro\bon\bn to run _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bm_\bo_\br_\be and
                 _\b/_\bu_\bs_\br_\b/_\bb_\bi_\bn_\b/_\bv_\bi with _\bn_\bo_\be_\bx_\be_\bc enabled.  This will pre­
                 vent those two commands from executing other
                 commands (such as a shell).  If you are unsure
                 whether or not your system is capable of sup­
                 porting _\bn_\bo_\be_\bx_\be_\bc you can always just try it out
                 and see if it works.

       Note that restricting shell escapes is not a panacea.
       Programs running as root are still capable of many poten­
       tially hazardous operations (such as changing or overwrit­
       ing files) that could lead to unintended privilege escala­
       tion.  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)

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 locks the file and does grammatical check­
       ing. It is imperative that _\bs_\bu_\bd_\bo_\be_\br_\bs be free of syntax
       errors since s\bsu\bud\bdo\bo will not run with a syntactically incor­
       rect _\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



1.6.9p10                December 17, 2007                      23





SUDOERS(4)             MAINTENANCE COMMANDS            SUDOERS(4)


       hostname 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
       If you feel you have found a bug in s\bsu\bud\bdo\bo, please submit a
       bug report at http://www.sudo.ws/sudo/bugs/

S\bSU\bUP\bPP\bPO\bOR\bRT\bT
       Limited free support is available via the sudo-users mail­
       ing list, see http://www.sudo.ws/mail­
       man/listinfo/sudo-users to subscribe or search the
       archives.

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 war­
       ranties, including, but not limited to, the implied war­
       ranties of merchantability and fitness for a particular
       purpose are disclaimed.  See the LICENSE file distributed
       with s\bsu\bud\bdo\bo or http://www.sudo.ws/sudo/license.html for com­
       plete details.





































1.6.9p10                December 17, 2007                      24