SUDO(8) BSD System Manager's Manual SUDO(8)
NAME
sudo, sudoedit — execute a command as another user
SYNOPSIS
sudo -h | -K | -k | -V
sudo -v [-ABkNnS] [-g group] [-h host] [-p prompt] [-u user]
sudo -l [-ABkNnS] [-g group] [-h host] [-p prompt] [-U user] [-u user]
[command [arg ...]]
sudo [-ABbEHnPS] [-C num] [-D directory] [-g group] [-h host] [-p prompt]
[-R directory] [-r role] [-t type] [-T timeout] [-u user]
[VAR=value] [-i | -s] [command [arg ...]]
sudoedit [-ABkNnS] [-C num] [-D directory] [-g group] [-h host]
[-p prompt] [-R directory] [-r role] [-t type] [-T timeout]
[-u user] file ...
DESCRIPTION
sudo allows a permitted user to execute a command as the superuser or an-
other user, as specified by the security policy. The invoking user's
real (not effective) user-ID is used to determine the user name with
which to query the security policy.
sudo supports a plugin architecture for security policies, auditing, and
input/output logging. Third parties can develop and distribute their own
plugins to work seamlessly with the sudo front-end. The default security
policy is sudoers, which is configured via the file /etc/sudoers, or via
LDAP. See the Plugins section for more information.
The security policy determines what privileges, if any, a user has to run
sudo. The policy may require that users authenticate themselves with a
password or another authentication mechanism. If authentication is re-
quired, sudo will exit if the user's password is not entered within a
configurable time limit. This limit is policy-specific; the default
password prompt timeout for the sudoers security policy is 0 minutes.
Security policies may support credential caching to allow the user to run
sudo again for a period of time without requiring authentication. By de-
fault, the sudoers policy caches credentials on a per-terminal basis for
15 minutes. See the timestamp_type and timestamp_timeout options in
sudoers(5) for more information. By running sudo with the -v option, a
user can update the cached credentials without running a command.
On systems where sudo is the primary method of gaining superuser privi-
leges, it is imperative to avoid syntax errors in the security policy
configuration files. For the default security policy, sudoers(5),
changes to the configuration files should be made using the visudo(8)
utility which will ensure that no syntax errors are introduced.
When invoked as sudoedit, the -e option (described below), is implied.
Security policies and audit plugins may log successful and failed at-
tempts to run sudo. If an I/O plugin is configured, the running
command's input and output may be logged as well.
The options are as follows:
-A, --askpass
Normally, if sudo requires a password, it will read it from the
user's terminal. If the -A (askpass) option is specified, a
(possibly graphical) helper program is executed to read the
user's password and output the password to the standard output.
If the SUDO_ASKPASS environment variable is set, it specifies the
path to the helper program. Otherwise, if sudo.conf(5) contains
a line specifying the askpass program, that value will be used.
For example:
# Path to askpass helper program
Path askpass /usr/X11R6/bin/ssh-askpass
If no askpass program is available, sudo will exit with an error.
-B, --bell
Ring the bell as part of the password prompt when a terminal is
present. This option has no effect if an askpass program is
used.
-b, --background
Run the given command in the background. It is not possible to
use shell job control to manipulate background processes started
by sudo. Most interactive commands will fail to work properly in
background mode.
-C num, --close-from=num
Close all file descriptors greater than or equal to num before
executing a command. Values less than three are not permitted.
By default, sudo will close all open file descriptors other than
standard input, standard output, and standard error when execut-
ing a command. The security policy may restrict the user's abil-
ity to use this option. The sudoers policy only permits use of
the -C option when the administrator has enabled the
closefrom_override option.
-D directory, --chdir=directory
Run the command in the specified directory instead of the current
working directory. The security policy may return an error if
the user does not have permission to specify the working direc-
tory.
-E, --preserve-env
Indicates to the security policy that the user wishes to preserve
their existing environment variables. The security policy may
return an error if the user does not have permission to preserve
the environment.
--preserve-env=list
Indicates to the security policy that the user wishes to add the
comma-separated list of environment variables to those preserved
from the user's environment. The security policy may return an
error if the user does not have permission to preserve the envi-
ronment. This option may be specified multiple times.
-e, --edit
Edit one or more files instead of running a command. In lieu of
a path name, the string "sudoedit" is used when consulting the
security policy. If the user is authorized by the policy, the
following steps are taken:
1. Temporary copies are made of the files to be edited with the
owner set to the invoking user.
2. The editor specified by the policy is run to edit the tempo-
rary files. The sudoers policy uses the SUDO_EDITOR, VISUAL
and EDITOR environment variables (in that order). If none
of SUDO_EDITOR, VISUAL or EDITOR are set, the first program
listed in the editor sudoers(5) option is used.
3. If they have been modified, the temporary files are copied
back to their original location and the temporary versions
are removed.
To help prevent the editing of unauthorized files, the following
restrictions are enforced unless explicitly allowed by the secu-
rity policy:
• Symbolic links may not be edited (version 1.8.15 and higher).
• Symbolic links along the path to be edited are not followed
when the parent directory is writable by the invoking user
unless that user is root (version 1.8.16 and higher).
• Files located in a directory that is writable by the invoking
user may not be edited unless that user is root (version
1.8.16 and higher).
Users are never allowed to edit device special files.
If the specified file does not exist, it will be created. Unlike
most commands run by sudo, the editor is run with the invoking
user's environment unmodified. If the temporary file becomes
empty after editing, the user will be prompted before it is in-
stalled. If, for some reason, sudo is unable to update a file
with its edited version, the user will receive a warning and the
edited copy will remain in a temporary file.
-g group, --group=group
Run the command with the primary group set to group instead of
the primary group specified by the target user's password data-
base entry. The group may be either a group name or a numeric
group-ID (GID) prefixed with the ‘#’ character (e.g., ‘#0’ for
GID 0). When running a command as a GID, many shells require
that the ‘#’ be escaped with a backslash (‘\’). If no -u option
is specified, the command will be run as the invoking user. In
either case, the primary group will be set to group. The sudoers
policy permits any of the target user's groups to be specified
via the -g option as long as the -P option is not in use.
-H, --set-home
Request that the security policy set the HOME environment vari-
able to the home directory specified by the target user's pass-
word database entry. Depending on the policy, this may be the
default behavior.
-h, --help
Display a short help message to the standard output and exit.
-h host, --host=host
Run the command on the specified host if the security policy
plugin supports remote commands. The sudoers plugin does not cur-
rently support running remote commands. This may also be used in
conjunction with the -l option to list a user's privileges for
the remote host.
-i, --login
Run the shell specified by the target user's password database
entry as a login shell. This means that login-specific resource
files such as .profile, .bash_profile, or .login will be read by
the shell. If a command is specified, it is passed to the shell
as a simple command using the -c option. The command and any
args are concatenated, separated by spaces, after escaping each
character (including white space) with a backslash (‘\’) except
for alphanumerics, underscores, hyphens, and dollar signs. If no
command is specified, an interactive shell is executed. sudo at-
tempts to change to that user's home directory before running the
shell. The command is run with an environment similar to the one
a user would receive at log in. Most shells behave differently
when a command is specified as compared to an interactive ses-
sion; consult the shell's manual for details. The Command
environment section in the sudoers(5) manual documents how the -i
option affects the environment in which a command is run when the
sudoers policy is in use.
-K, --remove-timestamp
Similar to the -k option, except that it removes every cached
credential for the user, regardless of the terminal or parent
process ID. The next time sudo is run, a password must be en-
tered if the security policy requires authentication. It is not
possible to use the -K option in conjunction with a command or
other option. This option does not require a password. Not all
security policies support credential caching.
-k, --reset-timestamp
When used without a command, invalidates the user's cached cre-
dentials for the current session. The next time sudo is run in
the session, a password must be entered if the security policy
requires authentication. By default, the sudoers policy uses a
separate record in the credential cache for each terminal (or
parent process ID if no terminal is present). This prevents the
-k option from interfering with sudo commands run in a different
terminal session. See the timestamp_type option in sudoers(5)
for more information. This option does not require a password,
and was added to allow a user to revoke sudo permissions from a
.logout file.
When used in conjunction with a command or an option that may re-
quire a password, this option will cause sudo to ignore the
user's cached credentials. As a result, sudo will prompt for a
password (if one is required by the security policy) and will not
update the user's cached credentials.
Not all security policies support credential caching.
-l, --list
If no command is specified, list the privileges for the invoking
user (or the user specified by the -U option) on the current
host. A longer list format is used if this option is specified
multiple times and the security policy supports a verbose output
format.
If a command is specified and is permitted by the security pol-
icy, the fully-qualified path to the command is displayed along
with any args. If a command is specified but not allowed by the
policy, sudo will exit with a status value of 1.
-N, --no-update
Do not update the user's cached credentials, even if the user
successfully authenticates. Unlike the -k flag, existing cached
credentials are used if they are valid. To detect when the
user's cached credentials are valid (or when no authentication is
required), the following can be used:
sudo -Nnv
Not all security policies support credential caching.
-n, --non-interactive
Avoid prompting the user for input of any kind. If a password is
required for the command to run, sudo will display an error mes-
sage and exit.
-P, --preserve-groups
Preserve the invoking user's group vector unaltered. By default,
the sudoers policy will initialize the group vector to the list
of groups the target user is a member of. The real and effective
group-IDs, however, are still set to match the target user.
-p prompt, --prompt=prompt
Use a custom password prompt with optional escape sequences. The
following percent (‘%’) escape sequences are supported by the
sudoers policy:
%H expanded to the host name including the domain name (only if
the machine's host name is fully qualified or the fqdn option
is set in sudoers(5))
%h expanded to the local host name without the domain name
%p expanded to the name of the user whose password is being re-
quested (respects the rootpw, targetpw, and runaspw flags in
sudoers(5))
%U expanded to the login name of the user the command will be
run as (defaults to root unless the -u option is also speci-
fied)
%u expanded to the invoking user's login name
%% two consecutive ‘%’ characters are collapsed into a single
‘%’ character
The custom prompt will override the default prompt specified by
either the security policy or the SUDO_PROMPT environment vari-
able. On systems that use PAM, the custom prompt will also over-
ride the prompt specified by a PAM module unless the
passprompt_override flag is disabled in sudoers.
-R directory, --chroot=directory
Change to the specified root directory (see chroot(8)) before
running the command. The security policy may return an error if
the user does not have permission to specify the root directory.
-r role, --role=role
Run the command with an SELinux security context that includes
the specified role.
-S, --stdin
Write the prompt to the standard error and read the password from
the standard input instead of using the terminal device.
-s, --shell
Run the shell specified by the SHELL environment variable if it
is set or the shell specified by the invoking user's password
database entry. If a command is specified, it is passed to the
shell as a simple command using the -c option. The command and
any args are concatenated, separated by spaces, after escaping
each character (including white space) with a backslash (‘\’) ex-
cept for alphanumerics, underscores, hyphens, and dollar signs.
If no command is specified, an interactive shell is executed.
Most shells behave differently when a command is specified as
compared to an interactive session; consult the shell's manual
for details.
-t type, --type=type
Run the command with an SELinux security context that includes
the specified type. If no type is specified, the default type is
derived from the role.
-U user, --other-user=user
Used in conjunction with the -l option to list the privileges for
user instead of for the invoking user. The security policy may
restrict listing other users' privileges. When using the sudoers
policy, the -U option is restricted to the root user and users
with either the “list” priviege for the specified user or the
ability to run any command as root or user on the current host.
-T timeout, --command-timeout=timeout
Used to set a timeout for the command. If the timeout expires
before the command has exited, the command will be terminated.
The security policy may restrict the user's ability to set time-
outs. The sudoers policy requires that user-specified timeouts
be explicitly enabled.
-u user, --user=user
Run the command as a user other than the default target user
(usually root). The user may be either a user name or a numeric
user-ID (UID) prefixed with the ‘#’ character (e.g., ‘#0’ for UID
0). When running commands as a UID, many shells require that the
‘#’ be escaped with a backslash (‘\’). Some security policies
may restrict UIDs to those listed in the password database. The
sudoers policy allows UIDs that are not in the password database
as long as the targetpw option is not set. Other security poli-
cies may not support this.
-V, --version
Print the sudo version string as well as the version string of
any configured plugins. If the invoking user is already root,
the -V option will display the options passed to configure when
sudo was built; plugins may display additional information such
as default options.
-v, --validate
Update the user's cached credentials, authenticating the user if
necessary. For the sudoers plugin, this extends the sudo timeout
for another 15 minutes by default, but does not run a command.
Not all security policies support cached credentials.
-- The -- is used to delimit the end of the sudo options. Subse-
quent options are passed to the command.
Options that take a value may only be specified once unless otherwise in-
dicated in the description. This is to help guard against problems
caused by poorly written scripts that invoke sudo with user-controlled
input.
Environment variables to be set for the command may also be passed as op-
tions to sudo in the form VAR=value, for example
LD_LIBRARY_PATH=/usr/local/pkg/lib. Environment variables may be subject
to restrictions imposed by the security policy plugin. The sudoers pol-
icy subjects environment variables passed as options to the same restric-
tions as existing environment variables with one important difference.
If the setenv option is set in sudoers, the command to be run has the
SETENV tag set or the command matched is ALL, the user may set variables
that would otherwise be forbidden. See sudoers(5) for more information.
COMMAND EXECUTION
When sudo executes a command, the security policy specifies the execution
environment for the command. Typically, the real and effective user and
group and IDs are set to match those of the target user, as specified in
the password database, and the group vector is initialized based on the
group database (unless the -P option was specified).
The following parameters may be specified by security policy:
• real and effective user-ID
• real and effective group-ID
• supplementary group-IDs
• the environment list
• current working directory
• file creation mode mask (umask)
• SELinux role and type
• scheduling priority (aka nice value)
Process model
There are two distinct ways sudo can run a command.
If an I/O logging plugin is configured to log terminal I/O, or if the se-
curity policy explicitly requests it, a new pseudo-terminal (“pty”) is
allocated and fork(2) is used to create a second sudo process, referred
to as the monitor. The monitor creates a new terminal session with it-
self as the leader and the pty as its controlling terminal, calls fork(2)
again, sets up the execution environment as described above, and then
uses the execve(2) system call to run the command in the child process.
The monitor exists to relay job control signals between the user's termi-
nal and the pty the command is being run in. This makes it possible to
suspend and resume the command normally. Without the monitor, the
command would be in what POSIX terms an “orphaned process group” and it
would not receive any job control signals from the kernel. When the
command exits or is terminated by a signal, the monitor passes the
command's exit status to the main sudo process and exits. After receiv-
ing the command's exit status, the main sudo process passes the command's
exit status to the security policy's close function, as well as the close
function of any configured audit plugin, and exits.
If no pty is used, sudo calls fork(2), sets up the execution environment
as described above, and uses the execve(2) system call to run the command
in the child process. The main sudo process waits until the command has
completed, then passes the command's exit status to the security policy's
close function, as well as the close function of any configured audit
plugins, and exits. As a special case, if the policy plugin does not de-
fine a close function, sudo will execute the command directly instead of
calling fork(2) first. The sudoers policy plugin will only define a
close function when I/O logging is enabled, a pty is required, an SELinux
role is specified, the command has an associated timeout, or the
pam_session or pam_setcred options are enabled. Both pam_session and
pam_setcred are enabled by default on systems using PAM.
On systems that use PAM, the security policy's close function is respon-
sible for closing the PAM session. It may also log the command's exit
status.
Signal handling
When the command is run as a child of the sudo process, sudo will relay
signals it receives to the command. The SIGINT and SIGQUIT signals are
only relayed when the command is being run in a new pty or when the sig-
nal was sent by a user process, not the kernel. This prevents the
command from receiving SIGINT twice each time the user enters control-C.
Some signals, such as SIGSTOP and SIGKILL, cannot be caught and thus will
not be relayed to the command. As a general rule, SIGTSTP should be used
instead of SIGSTOP when you wish to suspend a command being run by sudo.
As a special case, sudo will not relay signals that were sent by the
command it is running. This prevents the command from accidentally
killing itself. On some systems, the reboot(8) utility sends SIGTERM to
all non-system processes other than itself before rebooting the system.
This prevents sudo from relaying the SIGTERM signal it received back to
reboot(8), which might then exit before the system was actually rebooted,
leaving it in a half-dead state similar to single user mode. Note, how-
ever, that this check only applies to the command run by sudo and not any
other processes that the command may create. As a result, running a
script that calls reboot(8) or shutdown(8) via sudo may cause the system
to end up in this undefined state unless the reboot(8) or shutdown(8) are
run using the exec() family of functions instead of system() (which in-
terposes a shell between the command and the calling process).
Plugins
Plugins may be specified via Plugin directives in the sudo.conf(5) file.
They may be loaded as dynamic shared objects (on systems that support
them), or compiled directly into the sudo binary. If no sudo.conf(5)
file is present, or if it doesn't contain any Plugin lines, sudo will use
sudoers(5) for the policy, auditing, and I/O logging plugins. See the
sudo.conf(5) manual for details of the /etc/sudo.conf file and the
sudo_plugin(5) manual for more information about the sudo plugin archi-
tecture.
EXIT VALUE
Upon successful execution of a command, the exit status from sudo will be
the exit status of the program that was executed. If the command termi-
nated due to receipt of a signal, sudo will send itself the same signal
that terminated the command.
If the -l option was specified without a command, sudo will exit with a
value of 0 if the user is allowed to run sudo and they authenticated suc-
cessfully (as required by the security policy). If a command is speci-
fied with the -l option, the exit value will only be 0 if the command is
permitted by the security policy, otherwise it will be 1.
If there is an authentication failure, a configuration/permission prob-
lem, or if the given command cannot be executed, sudo exits with a value
of 1. In the latter case, the error string is printed to the standard
error. If sudo cannot stat(2) one or more entries in the user's PATH, an
error is printed to the standard error. (If the directory does not exist
or if it is not really a directory, the entry is ignored and no error is
printed.) This should not happen under normal circumstances. The most
common reason for stat(2) to return “permission denied” is if you are
running an automounter and one of the directories in your PATH is on a
machine that is currently unreachable.
SECURITY NOTES
sudo tries to be safe when executing external commands.
To prevent command spoofing, sudo checks "." and "" (both denoting cur-
rent directory) last when searching for a command in the user's PATH (if
one or both are in the PATH). Depending on the security policy, the
user's PATH environment variable may be modified, replaced, or passed un-
changed to the program that sudo executes.
Users should never be granted sudo privileges to execute files that are
writable by the user or that reside in a directory that is writable by
the user. If the user can modify or replace the command there is no way
to limit what additional commands they can run.
By default, sudo will only log the command it explicitly runs. If a user
runs a command such as ‘sudo su’ or ‘sudo sh’, subsequent commands run
from that shell are not subject to sudo's security policy. The same is
true for commands that offer shell escapes (including most editors). If
I/O logging is enabled, subsequent commands will have their input and/or
output logged, but there will not be traditional logs for those commands.
Because of this, care must be taken when giving users access to commands
via sudo to verify that the command does not inadvertently give the user
an effective root shell. For information on ways to address this, see
the Preventing shell escapes section in sudoers(5).
To prevent the disclosure of potentially sensitive information, sudo dis-
ables core dumps by default while it is executing (they are re-enabled
for the command that is run). This historical practice dates from a time
when most operating systems allowed set-user-ID processes to dump core by
default. To aid in debugging sudo crashes, you may wish to re-enable
core dumps by setting “disable_coredump” to false in the sudo.conf(5)
file as follows:
Set disable_coredump false
See the sudo.conf(5) manual for more information.
ENVIRONMENT
sudo utilizes the following environment variables. The security policy
has control over the actual content of the command's environment.
EDITOR Default editor to use in -e (sudoedit) mode if neither
SUDO_EDITOR nor VISUAL is set.
MAIL Set to the mail spool of the target user when the -i op-
tion is specified, or when env_reset is enabled in
sudoers (unless MAIL is present in the env_keep list).
HOME Set to the home directory of the target user when the -i
or -H options are specified, when the -s option is spec-
ified and set_home is set in sudoers, when
always_set_home is enabled in sudoers, or when env_reset
is enabled in sudoers and HOME is not present in the
env_keep list.
LOGNAME Set to the login name of the target user when the -i op-
tion is specified, when the set_logname option is en-
abled in sudoers, or when the env_reset option is en-
abled in sudoers (unless LOGNAME is present in the
env_keep list).
PATH May be overridden by the security policy.
SHELL Used to determine shell to run with -s option.
SUDO_ASKPASS Specifies the path to a helper program used to read the
password if no terminal is available or if the -A option
is specified.
SUDO_COMMAND Set to the command run by sudo, including any args. The
args are truncated at 4096 characters to prevent a po-
tential execution error.
SUDO_EDITOR Default editor to use in -e (sudoedit) mode.
SUDO_GID Set to the group-ID of the user who invoked sudo.
SUDO_PROMPT Used as the default password prompt unless the -p option
was specified.
SUDO_PS1 If set, PS1 will be set to its value for the program be-
ing run.
SUDO_UID Set to the user-ID of the user who invoked sudo.
SUDO_USER Set to the login name of the user who invoked sudo.
USER Set to the same value as LOGNAME, described above.
VISUAL Default editor to use in -e (sudoedit) mode if
SUDO_EDITOR is not set.
FILES
/etc/sudo.conf sudo front-end configuration
EXAMPLES
The following examples assume a properly configured security policy.
To get a file listing of an unreadable directory:
$ sudo ls /usr/local/protected
To list the home directory of user yaz on a machine where the file system
holding ~yaz is not exported as root:
$ sudo -u yaz ls ~yaz
To edit the index.html file as user www:
$ sudoedit -u www ~www/htdocs/index.html
To view system logs only accessible to root and users in the adm group:
$ sudo -g adm more /var/log/syslog
To run an editor as jim with a different primary group:
$ sudoedit -u jim -g audio ~jim/sound.txt
To shut down a machine:
$ sudo shutdown -r +15 "quick reboot"
To make a usage listing of the directories in the /home partition. The
commands are run in a sub-shell to allow the ‘cd’ command and file redi-
rection to work.
$ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
DIAGNOSTICS
Error messages produced by sudo include:
editing files in a writable directory is not permitted
By default, sudoedit does not permit editing a file when any of the
parent directories are writable by the invoking user. This avoids
a race condition that could allow the user to overwrite an arbi-
trary file. See the sudoedit_checkdir option in sudoers(5) for
more information.
editing symbolic links is not permitted
By default, sudoedit does not follow symbolic links when opening
files. See the sudoedit_follow option in sudoers(5) for more in-
formation.
effective uid is not 0, is sudo installed setuid root?
sudo was not run with root privileges. The sudo binary must be
owned by the root user and have the set-user-ID bit set. Also, it
must not be located on a file system mounted with the ‘nosuid’ op-
tion or on an NFS file system that maps uid 0 to an unprivileged
uid.
effective uid is not 0, is sudo on a file system with the 'nosuid' option
set or an NFS file system without root privileges?
sudo was not run with root privileges. The sudo binary has the
proper owner and permissions but it still did not run with root
privileges. The most common reason for this is that the file sys-
tem the sudo binary is located on is mounted with the ‘nosuid’ op-
tion or it is an NFS file system that maps uid 0 to an unprivileged
uid.
fatal error, unable to load plugins
An error occurred while loading or initializing the plugins speci-
fied in sudo.conf(5).
invalid environment variable name
One or more environment variable names specified via the -E option
contained an equal sign (‘=’). The arguments to the -E option
should be environment variable names without an associated value.
no password was provided
When sudo tried to read the password, it did not receive any char-
acters. This may happen if no terminal is available (or the -S op-
tion is specified) and the standard input has been redirected from
/dev/null.
a terminal is required to read the password
sudo needs to read the password but there is no mechanism available
for it to do so. A terminal is not present to read the password
from, sudo has not been configured to read from the standard input,
the -S option was not used, and no askpass helper has been speci-
fied either via the sudo.conf(5) file or the SUDO_ASKPASS environ-
ment variable.
no writable temporary directory found
sudoedit was unable to find a usable temporary directory in which
to store its intermediate files.
The “no new privileges” flag is set, which prevents sudo from running as
root.
sudo was run by a process that has the Linux “no new privileges”
flag is set. This causes the set-user-ID bit to be ignored when
running an executable, which will prevent sudo from functioning.
The most likely cause for this is running sudo within a container
that sets this flag. Check the documentation to see if it is pos-
sible to configure the container such that the flag is not set.
sudo must be owned by uid 0 and have the setuid bit set
sudo was not run with root privileges. The sudo binary does not
have the correct owner or permissions. It must be owned by the
root user and have the set-user-ID bit set.
sudoedit is not supported on this platform
It is only possible to run sudoedit on systems that support setting
the effective user-ID.
timed out reading password
The user did not enter a password before the password timeout (5
minutes by default) expired.
you do not exist in the passwd database
Your user-ID does not appear in the system passwd database.
you may not specify environment variables in edit mode
It is only possible to specify environment variables when running a
command. When editing a file, the editor is run with the user's
environment unmodified.
SEE ALSO
su(1), stat(2), login_cap(3), passwd(5), sudo.conf(5), sudo_plugin(5),
sudoers(5), sudoers_timestamp(5), sudoreplay(8), visudo(8)
HISTORY
See the HISTORY.md file in the sudo distribution
(https://www.sudo.ws/about/history/) for a brief history of sudo.
AUTHORS
Many people have worked on sudo over the years; this version consists of
code written primarily by:
Todd C. Miller
See the CONTRIBUTORS.md file in the sudo distribution
(https://www.sudo.ws/about/contributors/) for an exhaustive list of peo-
ple who have contributed to sudo.
CAVEATS
There is no easy way to prevent a user from gaining a root shell if that
user is allowed to run arbitrary commands via sudo. Also, many programs
(such as editors) allow the user to run commands via shell escapes, thus
avoiding sudo's checks. However, on most systems it is possible to pre-
vent shell escapes with the sudoers(5) plugin's noexec functionality.
It is not meaningful to run the ‘cd’ command directly via sudo, e.g.,
$ sudo cd /usr/local/protected
since when the command exits the parent process (your shell) will still
be the same. The -D option can be used to run a command in a specific
directory.
Running shell scripts via sudo can expose the same kernel bugs that make
set-user-ID shell scripts unsafe on some operating systems (if your OS
has a /dev/fd/ directory, set-user-ID shell scripts are generally safe).
BUGS
If you believe you have found a bug in sudo, you can submit a bug report
at https://bugzilla.sudo.ws/
SUPPORT
Limited free support is available via the sudo-users mailing list, see
https://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.md file
distributed with sudo or https://www.sudo.ws/about/license/ for complete
details.
Sudo 1.9.13p3 January 16, 2023 Sudo 1.9.13p3
Generated by dwww version 1.15 on Fri Jun 21 08:02:43 CEST 2024.