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SUDOERS(5)		  FreeBSD File Formats Manual		    SUDOERS(5)

NAME
     sudoers --	list of	which users may	execute	what

DESCRIPTION
     The sudoers file is composed of two types of entries: aliases (basically
     variables)	and user specifications	(which specify who may run what).

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

     The sudoers grammar will be described below in Extended Backus-Naur Form
     (EBNF).  Don't despair if you are unfamiliar with EBNF; it	is fairly sim-
     ple, and the definitions below are	annotated.

   Quick guide to EBNF
     EBNF is a concise and exact way of	describing the grammar of a language.
     Each EBNF definition is made up of	production rules.  E.g.,

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

     Each production rule references others and	thus makes up a	grammar	for
     the language.  EBNF also contains the following operators,	which many
     readers will recognize from regular expressions.  Do not, however,	con-
     fuse 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).

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

     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 alias	definition is of the form

     Alias_Type	NAME = item1, item2, ...

     where Alias_Type is one of	User_Alias, Runas_Alias, Host_Alias, or
     Cmnd_Alias.  A NAME is a string of	uppercase letters, numbers, and	under-
     score characters (`_').  A	NAME must start	with an	uppercase letter.  It
     is	possible to put	several	alias definitions of the same type on a	single
     line, joined by a colon (`:').  E.g.,

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

     The definitions of	what constitutes a valid alias member follow.

     User_List ::= User	|
		   User	',' User_List

     User ::= '!'* user	name |
	      '!'* #uid	|
	      '!'* %group |
	      '!'* %#gid |
	      '!'* +netgroup |
	      '!'* %:nonunix_group |
	      '!'* %:#nonunix_gid |
	      '!'* User_Alias

     A User_List is made up of one or more user	names, user ids	(prefixed with
     `#'), system group	names and ids (prefixed	with `%' and `%#' respec-
     tively), netgroups	(prefixed with `+'), non-Unix group names and IDs
     (prefixed with `%:' and `%:#' respectively) 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, uid, group, gid, netgroup, nonunix_group or nonunix_gid may
     be	enclosed in double quotes to avoid the need for	escaping special char-
     acters.  Alternately, special characters may be specified in escaped hex
     mode, e.g.	\x20 for space.	 When using double quotes, any prefix charac-
     ters must be included inside the quotes.

     The actual	nonunix_group and nonunix_gid syntax depends on	the underlying
     implementation.  For instance, the	QAS AD backend supports	the following
     formats:

     +o	   Group in the	same domain: "%:Group Name"

     +o	   Group in any	domain:	"%:Group Name@FULLY.QUALIFIED.DOMAIN"

     +o	   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	special	characters.  See Other
     special characters	and reserved words for a list of characters that need
     to	be escaped.

     Runas_List	::= Runas_Member |
		    Runas_Member ',' Runas_List

     Runas_Member ::= '!'* user	name |
		      '!'* #uid	|
		      '!'* %group |
		      '!'* %#gid |
		      '!'* %:nonunix_group |
		      '!'* %:#nonunix_gid |
		      '!'* +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 ::= '!'* host	name |
	      '!'* ip_addr |
	      '!'* network(/netmask)? |
	      '!'* +netgroup |
	      '!'* Host_Alias

     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, sudo will	query each of
     the local host's network interfaces and, if the network number corre-
     sponds to one of the hosts's network interfaces, the corresponding	net-
     mask 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 host name may	include	shell-
     style wildcards (see the Wildcards	section	below),	but unless the host
     name command on your machine returns the fully qualified host name,
     you'll need to use	the fqdn option	for wildcards to be useful.  Note that
     sudo only inspects	actual network interfaces; this	means that IP address
     127.0.0.1 (localhost) will	never match.  Also, the	host name
     ``localhost'' will	only match if that is the actual host name, which is
     usually only the case for non-networked systems.

     Cmnd_List ::= Cmnd	|
		   Cmnd	',' Cmnd_List

     command name ::= file name	|
		      file name	args |
		      file name	'""'

     Cmnd ::= '!'* command name	|
	      '!'* directory |
	      '!'* "sudoedit" |
	      '!'* Cmnd_Alias

     A Cmnd_List is a list of one or more command names, directories, and
     other aliases.  A command name is a fully qualified file name which may
     include shell-style wildcards (see	the Wildcards section below).  A sim-
     ple 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 without command line arguments.  A 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 sub-directories 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 char-
     acters must be escaped with a `\' if they are used	in command arguments:
     `,', `:', `=', `\'.  The special command ``sudoedit'' is used to permit a
     user to run sudo with the -e option (or as	sudoedit).  It may take	com-
     mand line arguments just as a normal command does.

   Defaults
     Certain configuration options may be changed from their default values at
     run-time 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 specific
     command, or commands being	run as a specific user.	 Note that per-command
     entries may not include command line arguments.  If you need to specify
     arguments,	define a Cmnd_Alias and	reference that instead.

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

     Default_Entry ::= Default_Type Parameter_List

     Parameter_List ::=	Parameter |
			Parameter ',' Parameter_List

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

     Parameters	may be flags, integer values, strings, or lists.  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	disable	them.  Values may be enclosed in double	quotes ("") when they
     contain multiple words.  Special characters may be	escaped	with a back-
     slash (`\').

     Lists have	two additional assignment operators, +=	and -=.	 These opera-
     tors 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.

     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.

   User	Specification
     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? (':' Runas_List)? ')'

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

     A user specification determines which commands a user may run (and	as
     what user)	on specified hosts.  By	default, commands are run as root, but
     this can be changed on a per-command basis.

     The basic structure of a user specification is ``who where	= (as_whom)
     what''.  Let's break that down into its constituent parts:

   Runas_Spec
     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	paren-
     theses.  The first	Runas_List indicates which users the command may be
     run as via	sudo's -u option.  The second defines a	list of	groups that
     can be specified via sudo's -g option.  If	both Runas_Lists are speci-
     fied, the command may be run with any combination of users	and groups
     listed in their respective	Runas_Lists. If	only the first is specified,
     the command may be	run as any user	in the list but	no -g option may be
     specified.	 If the	first Runas_List is empty but the second is specified,
     the command may be	run as the invoking user with the group	set to any
     listed in the Runas_List.	If no Runas_Spec is specified the command may
     be	run as root and	no group may be	specified.

     A Runas_Spec sets the default for the commands that follow	it.  What this
     means is that for the entry:

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

     The user dgb may run /bin/ls, /bin/kill, and /usr/bin/lprm--but only as
     operator.	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 dgb is now allowed to run /bin/ls as operator, but /bin/kill
     and /usr/bin/lprm as root.

     We	can extend this	to allow dgb to	run /bin/ls with either	the user or
     group set to operator:

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

     Note that while the group portion of the Runas_Spec permits the user to
     run as command with that group, it	does not force the user	to do so.  If
     no	group is specified on the command line,	the command will run with the
     group listed in the target	user's password	database entry.	 The following
     would all be permitted by the sudoers entry above:

     $ sudo -u operator	/bin/ls
     $ sudo -u operator	-g operator /bin/ls
     $ sudo -g operator	/bin/ls

     In	the following example, user tcm	may run	commands that access a modem
     device file with the dialer group.

     tcm     boulder = (:dialer) /usr/bin/tip, /usr/bin/cu,\
	     /usr/local/bin/minicom

     Note that in this example only the	group will be set, the command still
     runs as user tcm.	E.g.

     $ sudo -g dialer /usr/bin/cu

     Multiple users and	groups may be present in a Runas_Spec, in which	case
     the user may select any combination of users and groups via the -u	and -g
     options.  In this example:

     alan    ALL = (root, bin :	operator, system) ALL

     user alan may run any command as either user root or bin, optionally set-
     ting the group to operator	or system.

   Tag_Spec
     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 (in other words, PASSWD overrides NOPASSWD and	NOEXEC overrides
     EXEC).

     NOPASSWD and PASSWD

     By	default, sudo 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 ray to run /bin/kill,	/bin/ls, and /usr/bin/lprm as
     root on the machine rushmore without authenticating himself.  If we only
     want ray to be able to run	/bin/kill 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 exempt_group 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'' with-
     out 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
     pertain to	the current host.  This	behavior may be	overridden via the
     verifypw and listpw options.

     NOEXEC and	EXEC

     If	sudo has been compiled with noexec support and the underlying operat-
     ing system	supports it, the NOEXEC	tag can	be used	to prevent a dynami-
     cally-linked executable from running further commands itself.

     In	the following example, user aaron may run /usr/bin/more	and
     /usr/bin/vi 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.

     SETENV and	NOSETENV

     These tags	override the value of the setenv option	on a per-command
     basis.  Note that if SETENV has been set for a command, the user may dis-
     able the env_reset	option from the	command	line via the -E	option.	 Addi-
     tionally, environment variables set on the	command	line are not subject
     to	the restrictions imposed by env_check, env_delete, or env_keep.	 As
     such, only	trusted	users should be	allowed	to set variables in this man-
     ner.  If the command matched is ALL, the SETENV tag is implied for	that
     command; this default may be overridden by	use of the NOSETENV tag.

   Wildcards
     sudo allows shell-style wildcards (aka meta or glob characters) to	be
     used in host names, path names and	command	line arguments in the sudoers
     file.  Wildcard matching is done via the POSIX glob(3) and	fnmatch(3)
     routines.	Note that these	are not	regular	expressions.

     *	       Matches any set of zero or more characters.

     ?	       Matches any single character.

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

     [!...]    Matches any character not 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 glob(3) and
     fnmatch(3)	functions support them.	 However, because the `:' character
     has special meaning in sudoers, it	must be	escaped.  For example:

	 /bin/ls [[alpha]]*

     Would match any file name beginning with a	letter.

     Note that a forward slash (`/') will not be matched by wildcards used in
     the path name.  This is to	make a path like:

	 /usr/bin/*

     match /usr/bin/who	but not	/usr/bin/X11/xterm.

     When matching the command line arguments, however,	a slash	does get
     matched by	wildcards since	command	line arguments may contain arbitrary
     strings and not just path names.

     Wildcards in command line arguments should	be used	with care.  Because
     command line arguments are	matched	as a single, concatenated string, a
     wildcard such as `?' or `*' can match multiple words.  For	example, while
     a sudoers entry like:

	 %operator ALL = /bin/cat /var/log/messages*

     will allow	command	like:

	 $ sudo	cat /var/log/messages.1

     It	will also allow:

	 $ sudo	cat /var/log/messages /etc/shadow

     which is probably not what	was intended.

   Exceptions to wildcard rules
     The following exceptions apply to the above rules:

     ""	       If the empty string "" is the only command line argument	in the
	       sudoers entry it	means that command is not allowed to be	run
	       with any	arguments.

     sudoedit  Command line arguments to the sudoedit built-in command should
	       always be path names, so	a forward slash	(`/') will not be
	       matched by a wildcard.

   Including other files from within sudoers
     It	is possible to include other sudoers files from	within the sudoers
     file currently being parsed using the #include and	#includedir direc-
     tives.

     This can be used, for example, to keep a site-wide	sudoers	file in	addi-
     tion to a local, per-machine file.	 For the sake of this example the
     site-wide sudoers will be /etc/sudoers and	the per-machine	one will be
     /etc/sudoers.local.  To include /etc/sudoers.local	from within
     /etc/sudoers we would use the following line in /etc/sudoers:

	 #include /etc/sudoers.local

     When sudo reaches this line it will suspend processing of the current
     file (/etc/sudoers) and switch to /etc/sudoers.local.  Upon reaching the
     end of /etc/sudoers.local,	the rest of /etc/sudoers will be processed.
     Files that	are included may themselves include other files.  A hard limit
     of	128 nested include files is enforced to	prevent	include	file loops.

     If	the path to the	include	file is	not fully-qualified (does not begin
     with a `/', it must be located in the same	directory as the sudoers file
     it	was included from.  For	example, if /etc/sudoers contains the line:

	 #include sudoers.local

     the file that will	be included is /etc/sudoers.local.

     The file name may also include the	%h escape, signifying the short	form
     of	the host name.	In other words,	if the machine's host name is
     ``xerxes'', then

	 #include /etc/sudoers.%h

     will cause	sudo to	include	the file /etc/sudoers.xerxes.

     The #includedir directive can be used to create a sudo.d directory	that
     the system	package	manager	can drop sudoers rules into as part of package
     installation.  For	example, given:

	 #includedir /etc/sudoers.d

     sudo will read each file in /etc/sudoers.d, 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, /etc/sudoers.d/01_first will be parsed before
     /etc/sudoers.d/10_second.	Be aware that because the sorting is lexical,
     not numeric, /etc/sudoers.d/1_whoops would	be loaded after
     /etc/sudoers.d/10_second.	Using a	consistent number of leading zeroes in
     the file names can	be used	to avoid such problems.

     Note that unlike files included via #include, visudo will not edit	the
     files in a	#includedir directory unless one of them contains a syntax
     error.  It	is still possible to run visudo	with the -f flag to edit the
     files directly.

   Other special characters and	reserved words
     The pound sign (`#') is used to indicate a	comment	(unless	it is part of
     a #include	directive or unless it occurs in the context of	a user name
     and is followed by	one or more digits, in which case it is	treated	as a
     uid).  Both the comment character and any text after it, up to the	end of
     the line, are ignored.

     The reserved word ALL is a	built-in alias 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 alias called ALL as the built-in alias will be used in prefer-
     ence to your own.	Please note that using ALL can be dangerous since in a
     command context, it allows	the user to run	any command on the system.

     An	exclamation point (`!')	can be used as a logical not operator both in
     an	alias and in front of a	Cmnd.  This allows one to exclude certain val-
     ues.  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.

     White space between elements in a list as well as special syntactic char-
     acters in a User Specification (`=', `:', `(', `)') is optional.

     The following characters must be escaped with a backslash (`\') when used
     as	part of	a word (e.g. a user name or host name):	`!', `=', `:', `,',
     `(', `)', `\'.

SUDOERS	OPTIONS
     sudo's behavior can be modified by	Default_Entry lines, as	explained ear-
     lier.  A list of all supported Defaults parameters, grouped by type, are
     listed below.

     Boolean Flags:

     always_set_home   If enabled, sudo	will set the HOME environment variable
		       to the home directory of	the target user	(which is root
		       unless the -u option is used).  This effectively	means
		       that the	-H option is always implied.  This flag	is off
		       by default.

     authenticate      If set, users must authenticate themselves via a	pass-
		       word (or	other means of authentication) before they may
		       run commands.  This default may be overridden via the
		       PASSWD and NOPASSWD tags.  This flag is on by default.

     closefrom_override
		       If set, the user	may use	sudo's -C option which over-
		       rides the default starting point	at which sudo begins
		       closing open file descriptors.  This flag is off	by
		       default.

     env_editor	       If set, visudo will use the value of the	EDITOR or
		       VISUAL environment variables before falling back	on the
		       default editor list.  Note that this may	create a 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.	 visudo	will then only use the EDITOR
		       or VISUAL if they match a value specified in editor.
		       This flag is on by default.

     env_reset	       If set, sudo will run the command in a minimal environ-
		       ment containing the TERM, PATH, HOME, MAIL, SHELL,
		       LOGNAME,	USER, USERNAME and SUDO_* variables.  Any
		       variables in the	caller's environment that match	the
		       env_keep	and env_check lists are	then added, followed
		       by any variables	present	in the file specified by the
		       env_file	option (if any).  The default contents of the
		       env_keep	and env_check lists are	displayed when sudo is
		       run by root with	the -V option.	If the secure_path
		       option is set, its value	will be	used for the PATH
		       environment variable.  This flag	is on by default.

     fast_glob	       Normally, sudo uses the glob(3) function	to do shell-
		       style globbing when matching path names.	 However,
		       since it	accesses the file system, glob(3) can take a
		       long time to complete for some patterns,	especially
		       when the	pattern	references a network file system that
		       is mounted on demand (auto mounted).  The fast_glob
		       option causes sudo to use the fnmatch(3)	function,
		       which does not access the file system to	do its match-
		       ing.  The disadvantage of fast_glob is that it is
		       unable to match relative	path names such	as ./ls	or
		       ../bin/ls.  This	has security implications when path
		       names that include globbing characters are used with
		       the negation operator, `!', as such rules can be	triv-
		       ially bypassed.	As such, this option should not	be
		       used when sudoers contains rules	that contain negated
		       path names which	include	globbing characters.  This
		       flag is off by default.

     fqdn	       Set this	flag if	you want to put	fully qualified	host
		       names in	the sudoers file when the local	host name (as
		       returned	by the hostname	command) does not contain the
		       domain name.  In	other words, instead of	myhost you
		       would use myhost.mydomain.edu.  You may still use the
		       short form if you wish (and even	mix the	two).  This
		       option is only effective	when the ``canonical'' host
		       name, as	returned by the	getaddrinfo() or
		       gethostbyname() function, is a fully-qualified domain
		       name.  This is usually the case when the	system is con-
		       figured to use DNS for host name	resolution.

		       If the system is	configured to use the /etc/hosts file
		       in preference to	DNS, the ``canonical'' host name may
		       not be fully-qualified.	The order that sources are
		       queried for hosts name resolution is specified in the
		       /etc/resolv.conf	file.  In the /etc/hosts file, the
		       first host name of the entry is considered to be	the
		       ``canonical'' name; subsequent names are	aliases	that
		       are not used by sudoers.	 For example, the following
		       hosts file line for the machine ``xyzzy'' has the
		       fully-qualified domain name as the ``canonical''	host
		       name, and the short version as an alias.

			     192.168.1.1    xyzzy.sudo.ws xyzzy

		       If the machine's	hosts file entry is not	formatted
		       properly, the fqdn option will not be effective if it
		       is queried before DNS.

		       Beware that when	using DNS for host name	resolution,
		       turning on fqdn requires	sudoers	to make	DNS lookups
		       which renders sudo unusable if DNS stops	working	(for
		       example if the machine is disconnected from the net-
		       work).  Also note that just like	with the hosts file,
		       you must	use the	``canonical'' 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.

		       This flag is off	by default.

     ignore_dot	       If set, sudo will ignore	"." or "" (both	denoting cur-
		       rent directory) in the PATH environment variable; the
		       PATH itself is not modified.  This flag is off by
		       default.

     ignore_local_sudoers
		       If set via LDAP,	parsing	of /etc/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	opera-
		       tors who	would attempt to add roles to /etc/sudoers.
		       When this option	is present, /etc/sudoers does not even
		       need to exist.  Since this option tells sudo how	to
		       behave when no specific LDAP entries have been matched,
		       this sudoOption is only meaningful for the cn=defaults
		       section.	 This flag is off by default.

     insults	       If set, sudo will insult	users when they	enter an
		       incorrect password.  This flag is on by default.

     log_host	       If set, the host	name will be logged in the (non-sys-
		       log) sudo log file.  This flag is off by	default.

     log_year	       If set, the four-digit year will	be logged in the (non-
		       syslog) sudo log	file.  This flag is off	by default.

     long_otp_prompt   When validating with a One Time Password	(OTP) scheme
		       such as S/Key or	OPIE, a	two-line prompt	is used	to
		       make it easier to cut and paste the challenge to	a
		       local window.  It's not as pretty as the	default	but
		       some people find	it more	convenient.  This flag is off
		       by default.

     mail_always       Send mail to the	mailto user every time a users runs
		       sudo.  This flag	is off by default.

     mail_badpass      Send mail to the	mailto user if the user	running	sudo
		       does not	enter the correct password.  If	the command
		       the user	is attempting to run is	not permitted by
		       sudoers and one of the mail_always, mail_no_host,
		       mail_no_perms or	mail_no_user flags are set, this flag
		       will have no effect.  This flag is off by default.

     mail_no_host      If set, mail will be sent to the	mailto user if the
		       invoking	user exists in the sudoers file, but is	not
		       allowed to run commands on the current host.  This flag
		       is off by default.

     mail_no_perms     If set, mail will be sent to the	mailto user if the
		       invoking	user is	allowed	to use sudo but	the command
		       they are	trying is not listed in	their sudoers file
		       entry or	is explicitly denied.  This flag is off	by
		       default.

     mail_no_user      If set, mail will be sent to the	mailto user if the
		       invoking	user is	not in the sudoers file.  This flag is
		       on by default.

     noexec	       If set, all commands run	via sudo will behave as	if the
		       NOEXEC tag has been set,	unless overridden by a EXEC
		       tag.  See the description of NOEXEC and EXEC below as
		       well as the Preventing Shell Escapes section at the end
		       of this manual.	This flag is off by default.

     path_info	       Normally, sudo 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 executables that
		       the normal user does not	have access to.	 The disadvan-
		       tage is that if the executable is simply	not in the
		       user's PATH, sudo will tell the user that they are not
		       allowed to run it, which	can be confusing.  This	flag
		       is off by default.

     passprompt_override
		       The password prompt specified by	passprompt will	nor-
		       mally only be used if the password prompt provided by
		       systems such as PAM matches the string ``Password:''.
		       If passprompt_override is set, passprompt will always
		       be used.	 This flag is off by default.

     preserve_groups   By default, sudo	will initialize	the group vector to
		       the list	of groups the target user is in.  When
		       preserve_groups is set, the user's existing group vec-
		       tor is left unaltered.  The real	and effective group
		       IDs, however, are still set to match the	target user.
		       This flag is off	by default.

     pwfeedback	       By default, sudo	reads the password like	most other
		       Unix programs, by turning off echo until	the user hits
		       the return (or enter) key.  Some	users become confused
		       by this as it appears to	them that sudo has hung	at
		       this point.  When pwfeedback is set, sudo will provide
		       visual feedback when the	user presses a key.  Note that
		       this does have a	security impact	as an onlooker may be
		       able to determine the length of the password being
		       entered.	 This flag is off by default.

     requiretty	       If set, sudo will only run when the user	is logged in
		       to a real tty.  When this flag is set, sudo can only be
		       run from	a login	session	and not	via other means	such
		       as cron(8) or cgi-bin scripts.  This flag is off	by
		       default.

     root_sudo	       If set, root is allowed to run sudo too.	 Disabling
		       this prevents users from	``chaining'' sudo commands to
		       get a root shell	by doing something like	``sudo sudo
		       /bin/sh''.  Note, however, that turning off root_sudo
		       will also prevent root from running sudoedit.  Dis-
		       abling root_sudo	provides no real additional security;
		       it exists purely	for historical reasons.	 This flag is
		       on by default.

     rootpw	       If set, sudo will prompt	for the	root password instead
		       of the password of the invoking user.  This flag	is off
		       by default.

     runaspw	       If set, sudo will prompt	for the	password of the	user
		       defined by the runas_default option (defaults to	root)
		       instead of the password of the invoking user.  This
		       flag is off by default.

     set_home	       If enabled and sudo is invoked with the -s option the
		       HOME environment	variable will be set to	the home
		       directory of the	target user (which is root unless the
		       -u option is used).  This effectively makes the -s
		       option imply -H.	 This flag is off by default.

     set_logname       Normally, sudo will set the LOGNAME, USER and USERNAME
		       environment variables to	the name of the	target user
		       (usually	root unless the	-u option 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 behavior.
		       This can	be done	by negating the	set_logname option.
		       Note that if the	env_reset option has not been dis-
		       abled, entries in the env_keep list will	override the
		       value of	set_logname.  This flag	is on by default.

     setenv	       Allow the user to disable the env_reset option from the
		       command line via	the -E option.	Additionally, environ-
		       ment variables set via the command line are not subject
		       to the restrictions imposed by env_check, env_delete,
		       or env_keep.  As	such, only trusted users should	be
		       allowed to set variables	in this	manner.	 This flag is
		       off by default.

     shell_noargs      If set and sudo is invoked with no arguments it acts as
		       if the -s option	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 user's /etc/passwd entry
		       if not).	 This flag is off by default.

     stay_setuid       Normally, when sudo 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 sudo act	as a setuid wrapper.
		       This can	be useful on systems that disable some poten-
		       tially dangerous	functionality when a program is	run
		       setuid.	This option is only effective on systems that
		       support either the setreuid(2) or setresuid(2) system
		       call.  This flag	is off by default.

     targetpw	       If set, sudo will prompt	for the	password of the	user
		       specified by the	-u option (defaults to root) instead
		       of the password of the invoking user.  In addition, the
		       time stamp 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
		       -u option.  This	flag is	off by default.

     tty_tickets       If set, users must authenticate on a per-tty basis.
		       With this flag enabled, sudo will use a file named for
		       the tty the user	is logged in on	in the user's time
		       stamp directory.	 If disabled, the time stamp of	the
		       directory is used instead.  This	flag is	off by
		       default.

     umask_override    If set, sudo will set the umask as specified by sudoers
		       without modification.  This makes it possible to	spec-
		       ify a more permissive umask in sudoers than the user's
		       own umask and matches historical	behavior.  If
		       umask_override is not set, sudo will set	the umask to
		       be the union of the user's umask	and what is specified
		       in sudoers.  This flag is off by	default.

     use_loginclass    If set, sudo will apply the defaults specified for the
		       target user's login class if one	exists.	 Only avail-
		       able if sudo is configured with the --with-logincap
		       option.	This flag is off by default.

     use_pty	       If set, sudo will run the command in a pseudo-pty even
		       if no I/O logging is being gone.	 A malicious program
		       run under sudo could conceivably	fork a background
		       process that retains to the user's terminal device
		       after the main program has finished executing.  Use of
		       this option will	make that impossible.  This flag is
		       off by default.

     visiblepw	       By default, sudo	will refuse to run if the user must
		       enter a password	but it is not possible to disable echo
		       on the terminal.	 If the	visiblepw flag is set, sudo
		       will prompt for a password even when it would be	visi-
		       ble on the screen.  This	makes it possible to run
		       things like ``ssh somehost sudo ls'' since by default,
		       ssh(1) does not allocate	a tty when running a command.
		       This flag is off	by default.

     Integers:

     closefrom	       Before it executes a command, sudo will close all open
		       file descriptors	other than standard input, standard
		       output and standard error (ie: file descriptors 0-2).
		       The closefrom option can	be used	to specify a different
		       file descriptor at which	to start closing.  The default
		       is 3.

     passwd_tries      The number of tries a user gets to enter	his/her	pass-
		       word before sudo	logs the failure and exits.  The
		       default is 3.

     Integers that can be used in a boolean context:

     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).

     passwd_timeout    Number of minutes before	the sudo password prompt times
		       out, or 0 for no	timeout.  The timeout may include a
		       fractional component if minute granularity is insuffi-
		       cient, for example 2.5.	The default is 5.

     timestamp_timeout
		       Number of minutes that can elapse before	sudo will ask
		       for a passwd again.  The	timeout	may include a frac-
		       tional 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 time stamp will never expire.	This
		       can be used to allow users to create or delete their
		       own time	stamps 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 actual umask	that is	used will be the union of the
		       user's umask and	the value of the umask option, which
		       defaults	to 022.	 This guarantees that sudo never low-
		       ers the umask when running a command.  Note: on systems
		       that use	PAM, the default PAM configuration may specify
		       its own umask which will	override the value set in
		       sudoers.

     Strings:

     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 visudo.  visudo 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 /usr/bin/vi.

     mailsub	       Subject of the mail sent	to the mailto user.  The
		       escape %h will expand to	the host name of the machine.
		       Default is ``***	SECURITY information for %h ***''.

     noexec_file       The noexec option specifies the the fully-qualified
		       path to a shared	library	containing dummy versions of
		       the execv(), execve() and fexecve() library functions
		       that just return	an error.  This	is used	to implement
		       the noexec functionality	on systems that	support
		       LD_PRELOAD or its equivalent.  Defaults to
		       /usr/libexec/sudo_noexec.so..

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

		       %H    expanded to the local host	name including the
			     domain name (only if the machine's	host name is
			     fully qualified or	the fqdn option	is set)

		       %h    expanded to the local host	name without the
			     domain name

		       %p    expanded to the user whose	password is being
			     asked for (respects the rootpw, targetpw and
			     runaspw flags in sudoers)

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

		       %u    expanded to the invoking user's login name

		       %%    two consecutive % characters are collapsed	into a
			     single % character

		       The default value is ``Password:''.

     runas_default     The default user	to run commands	as if the -u option is
		       not specified on	the command line.  This	defaults to
		       root.

     syslog_badpri     Syslog priority to use when user	authenticates unsuc-
		       cessfully.  Defaults to alert.

		       The following syslog priorities are supported: alert,
		       crit, debug, emerg, err,	info, notice, and warning.

     syslog_goodpri    Syslog priority to use when user	authenticates success-
		       fully.  Defaults	to notice.

		       See syslog_badpri for the list of supported syslog pri-
		       orities.

     sudoers_locale    Locale to use when parsing the sudoers file, logging
		       commands, and sending email.  Note that changing	the
		       locale may affect how sudoers is	interpreted.  Defaults
		       to ``C''.

     timestampdir      The directory in	which sudo stores its time stamp
		       files.  The default is /var/run/sudo.

     timestampowner    The owner of the	time stamp directory and the time
		       stamps stored therein.  The default is root.

     askpass	       The askpass option specifies the	fully qualified	path
		       to a helper program used	to read	the user's password
		       when no terminal	is available.  This may	be the case
		       when sudo is executed from a graphical (as opposed to
		       text-based) application.	 The program specified by
		       askpass should display the argument passed to it	as the
		       prompt and write	the user's password to the standard
		       output.	The value of askpass may be overridden by the
		       SUDO_ASKPASS environment	variable.

     env_file	       The env_file option specifies the fully qualified path
		       to a file containing variables to be set	in the envi-
		       ronment of 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 sudo environment set-
		       tings such as env_keep and env_check.

     exempt_group      Users in	this group are exempt from password and	PATH
		       requirements.  The group	name specified should not
		       include a % prefix.  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.

		       once    Only lecture the	user the first time they run
			       sudo.

		       If no value is specified, a value of once is implied.
		       Negating	the option results in a	value of never being
		       used.  The default value	is on.

     lecture_file      Path to a file containing an alternate sudo lecture
		       that will be used in place of the standard lecture if
		       the named file exists.  By default, sudo	uses a built-
		       in lecture.

     listpw	       This option controls when a password will be required
		       when a user runs	sudo with the -l option.  It has the
		       following possible values:

		       all	 All the user's	sudoers	entries	for the	cur-
				 rent host must	have the NOPASSWD flag set to
				 avoid entering	a password.

		       always	 The user must always enter a password to use
				 the -l	option.

		       any	 At least one of the user's sudoers entries
				 for the current host must have	the NOPASSWD
				 flag set to avoid entering a password.

		       never	 The user need never enter a password to use
				 the -l	option.

		       If no value is specified, a value of any	is implied.
		       Negating	the option results in a	value of never being
		       used.  The default value	is any.

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

     mailerflags       Flags to	use when invoking mailer. Defaults to -t.

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

     mailfrom	       Address to use for the ``from'' address when sending
		       warning and error mail.	The address should be enclosed
		       in double quotes	("") to	protect	against	sudo inter-
		       preting the @ sign.  Defaults to	the name of the	user
		       running sudo.

     mailto	       Address to send warning and error mail to.  The address
		       should be enclosed in double quotes ("")	to protect
		       against sudo interpreting the @ sign.  Defaults to
		       root.

     secure_path       Path used for every command run from sudo.  If you
		       don't trust the people running sudo to have a sane PATH
		       environment variable you	may want to use	this.  Another
		       use is if you want to have the ``root path'' be sepa-
		       rate from the ``user path''.  Users in the group	speci-
		       fied by the exempt_group	option are not affected	by
		       secure_path.  This option is not	set by default.

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

		       The following syslog facilities are supported: authpriv
		       (if your	OS supports it), auth, daemon, user, local0,
		       local1, local2, local3, local4, local5, local6, and
		       local7.

     verifypw	       This option controls when a password will be required
		       when a user runs	sudo with the -v option.  It has the
		       following possible values:

		       all     All the user's sudoers 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 -v option.

		       any     At least	one of the user's sudoers entries for
			       the current host	must have the NOPASSWD flag
			       set to avoid entering a password.

		       never   The user	need never enter a password to use the
			       -v option.

		       If no value is specified, a value of all	is implied.
		       Negating	the option results in a	value of never being
		       used.  The default value	is all.

     Lists that	can be used in a boolean context:

     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 pro-
		       grams.  The argument may	be a double-quoted, space-sep-
		       arated 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.  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	sudo
		       is run by root with the -V option.

     env_delete	       Environment variables to	be removed from	the user's
		       environment when	the env_reset option is	not in effect.
		       The argument may	be a double-quoted, space-separated
		       list or a single	value without double-quotes.  The list
		       can be replaced,	added to, deleted from,	or disabled by
		       using the =, +=,	-=, and	! operators respectively.  The
		       default list of environment variables to	remove is dis-
		       played when sudo	is run by root with the	-V option.
		       Note that many operating	systems	will remove poten-
		       tially dangerous	variables from the environment of any
		       setuid process (such as sudo).

     env_keep	       Environment variables to	be preserved in	the user's
		       environment when	the env_reset option is	in effect.
		       This allows fine-grained	control	over the environment
		       sudo-spawned processes will receive.  The argument may
		       be a double-quoted, space-separated list	or a single
		       value without double-quotes.  The list can be replaced,
		       added to, deleted from, or disabled by using the	=, +=,
		       -=, and ! operators respectively.  The default list of
		       variables to keep is displayed when sudo	is run by root
		       with the	-V option.

FILES
     /etc/sudoers	       List of who can run what

     /etc/group		       Local groups file

     /etc/netgroup	       List of network groups

EXAMPLES
     Below are example sudoers entries.	 Admittedly, some of these are a bit
     contrived.	 First,	we allow a few environment variables to	pass and then
     define our	aliases:

     # Run X applications through sudo;	HOME is	used to	find the
     # .Xauthority file.  Note that other programs use HOME to find
     # configuration files and this may	lead to	privilege escalation!
     Defaults env_keep += "DISPLAY HOME"

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

     # 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 :\
		     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 sudo to
     log via syslog(3) using the auth facility in all cases.  We don't want to
     subject the full time staff to the	sudo lecture, user millert 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 SERVERS 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 (/usr/bin/more, /usr/bin/pg and
     /usr/bin/less).

     # 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 User specification is the part	that actually determines who may run
     what.

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

     We	let root and any user in group wheel run any command on	any host as
     any user.

     FULLTIMERS	     ALL = NOPASSWD: ALL

     Full time sysadmins (millert, mikef, and dowdy) may run any command on
     any host without authenticating themselves.

     PARTTIMERS	     ALL = ALL

     Part time sysadmins bostley, jwfox, and crawl) may	run any	command	on any
     host but they must	authenticate themselves	first (since the entry lacks
     the NOPASSWD tag).

     jack	     CSNETS = ALL

     The user jack may run any command on the machines in the CSNETS 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 CSNETS,
     the local machine's netmask will be used during matching.

     lisa	     CUNETS = ALL

     The user lisa may run any command on any host in the CUNETS alias (the
     class B network 128.138.0.0).

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

     The operator user may run commands	limited	to simple maintenance.	Here,
     those are commands	related	to backups, killing processes, the printing
     system, shutting down the system, and any commands	in the directory
     /usr/oper/bin/.

     joe	     ALL = /usr/bin/su operator

     The user joe may only su(1) to operator.

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

     %opers	     ALL = (: ADMINGRP)	/usr/sbin/

     Users in the opers	group may run commands in /usr/sbin/ as	themselves
     with any group in the ADMINGRP Runas_Alias	(the adm and oper groups).

     The user pete is allowed to change	anyone's password except for root on
     the HPPA machines.	 Note that this	assumes	passwd(1) does not take	multi-
     ple user names on the command line.

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

     The user bob may run anything on the SPARC	and SGI	machines as any	user
     listed in the OP Runas_Alias (root	and operator.)

     jim	     +biglab = ALL

     The user jim may run any command on machines in the biglab	netgroup.
     sudo knows	that ``biglab''	is a netgroup due to the `+' prefix.

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

     Users in the secretaries 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 fred can run commands as any user	in the DB Runas_Alias (oracle
     or	sybase)	without	giving a password.

     john	     ALPHA = /usr/bin/su [!-]*,	!/usr/bin/su *root*

     On	the ALPHA machines, user john may su to	anyone except root but he is
     not allowed to specify any	options	to the su(1) command.

     jen	     ALL, !SERVERS = ALL

     The user jen may run any command on any machine except for	those in the
     SERVERS Host_Alias	(master, mail, www and ns).

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

     For any machine in	the SERVERS Host_Alias,	jill may run any commands in
     the directory /usr/bin/ except for	those commands belonging to the	SU and
     SHELLS Cmnd_Aliases.

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

     The user steve may	run any	command	in the directory /usr/local/op_com-
     mands/ but	only as	user operator.

     matt	     valkyrie =	KILL

     On	his personal workstation, valkyrie, matt 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 WEBMASTERS User_Alias (will, wendy, and
     wim), may run any command as user www (which owns the web pages) or sim-
     ply su(1) to www.

     ALL	     CDROM = NOPASSWD: /sbin/umount /CDROM,\
		     /sbin/mount -o nosuidnodev	/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 type, so it is a prime candidate for	encap-
     sulating in a shell script.

SECURITY NOTES
   Limitations of the `!' operator
     It	is generally not effective to ``subtract'' commands from ALL using the
     `!' operator.  A user can trivially circumvent this by copying the
     desired command to	a different name and then executing that.  For exam-
     ple:

     bill    ALL = ALL,	!SU, !SHELLS

     Doesn't really prevent bill from running the commands listed in SU	or
     SHELLS 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 rein-
     forced by policy).

     In	general, if a user has sudo ALL	there is nothing to prevent them from
     creating their own	program	that gives them	a root shell (or making	their
     own copy of a shell) regardless of	any `!'	elements in the	user specifi-
     cation.

   Security implications of fast_glob
     If	the fast_glob option is	in use,	it is not possible to reliably negate
     commands where the	path name includes globbing (aka wildcard) characters.
     This is because the C library's fnmatch(3)	function cannot	resolve	rela-
     tive paths.  While	this is	typically only an inconvenience	for rules that
     grant privileges, it can result in	a security issue for rules that	sub-
     tract or revoke privileges.

     For example, given	the following sudoers entry:

     john    ALL = /usr/bin/passwd [a-zA-Z0-9]*, /usr/bin/chsh [a-zA-Z0-9]*,\
		   /usr/bin/chfn [a-zA-Z0-9]*, !/usr/bin/* root

     User john can still run /usr/bin/passwd root if fast_glob is enabled by
     changing to /usr/bin and running ./passwd root instead.

   Preventing Shell Escapes
     Once sudo executes	a program, that	program	is free	to do whatever it
     pleases, including	run other programs.  This can be a security issue
     since it is not uncommon for a program to allow shell escapes, which lets
     a user bypass sudo's access control and logging.  Common programs that
     permit shell escapes include shells (obviously), editors, paginators,
     mail and terminal programs.

     There are two basic approaches to this problem:

     restrict  Avoid giving users access to commands that allow	the user to
	       run arbitrary commands.	Many editors have a restricted mode
	       where shell escapes are disabled, though	sudoedit is a better
	       solution	to running editors via sudo.  Due to the large number
	       of programs that	offer shell escapes, restricting users to the
	       set of programs that do not is often unworkable.

     noexec    Many systems that support shared	libraries have the ability to
	       override	default	library	functions by pointing an environment
	       variable	(usually LD_PRELOAD) to	an alternate shared library.
	       On such systems,	sudo's noexec functionality can	be used	to
	       prevent a program run by	sudo from executing any	other pro-
	       grams.  Note, however, that this	applies	only to	native dynami-
	       cally-linked executables.  Statically-linked executables	and
	       foreign executables running under binary	emulation are not
	       affected.

	       The noexec feature is known to work on SunOS, Solaris, *BSD,
	       Linux, IRIX, Tru64 UNIX,	MacOS X, HP-UX 11.x and	AIX 5.3	and
	       above.  It should be supported on most operating	systems	that
	       support the LD_PRELOAD environment variable.  Check your	oper-
	       ating 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 supported.

	       To enable noexec	for a command, use the NOEXEC tag as docu-
	       mented in the User Specification	section	above.	Here is	that
	       example again:

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

	       This allows user	aaron to run /usr/bin/more and /usr/bin/vi
	       with noexec enabled.  This will prevent those two commands from
	       executing other commands	(such as a shell).  If you are unsure
	       whether or not your system is capable of	supporting noexec you
	       can always just try it out and check whether shell escapes work
	       when noexec is enabled.

     Note that restricting shell escapes is not	a panacea.  Programs running
     as	root are still capable of many potentially hazardous operations	(such
     as	changing or overwriting	files) that could lead to unintended privilege
     escalation.  In the specific case of an editor, a safer approach is to
     give the user permission to run sudoedit.

SEE ALSO
     ssh(1), su(1), fnmatch(3),	glob(3), mktemp(3), strftime(3),
     sudoers.ldap(5), sudo(8), visudo(8)

CAVEATS
     The sudoers file should always be edited by the visudo command which
     locks the file and	does grammatical checking.  It is imperative that
     sudoers be	free of	syntax errors since sudo will not run with a syntacti-
     cally incorrect sudoers file.

     When using	netgroups of machines (as opposed to users), if	you store
     fully qualified host name in the netgroup (as is usually the case), you
     either need to have the machine's host name be fully qualified as
     returned by the hostname command or use the fqdn option in	sudoers.

BUGS
     If	you feel you have found	a bug in sudo, please submit a bug report at
     http://www.sudo.ws/sudo/bugs/

SUPPORT
     Limited free support is available via the sudo-users mailing list,	see
     http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search the
     archives.

DISCLAIMER
     sudo is provided ``AS IS''	and any	express	or implied warranties, includ-
     ing, but not limited to, the implied warranties of	merchantability	and
     fitness for a particular purpose are disclaimed.  See the LICENSE file
     distributed with sudo or http://www.sudo.ws/sudo/license.html for com-
     plete details.

FreeBSD	9.2			April 20, 2014			   FreeBSD 9.2

NAME | DESCRIPTION | SUDOERS OPTIONS | FILES | EXAMPLES | SECURITY NOTES | SEE ALSO | CAVEATS | BUGS | SUPPORT | DISCLAIMER

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