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NAME | SYNOPSIS | DESCRIPTION | COMMAND EXECUTION | EXIT VALUE | SECURITY NOTES | ENVIRONMENT | FILES | EXAMPLES | DIAGNOSTICS | SEE ALSO | HISTORY | AUTHORS | CAVEATS | BUGS | SUPPORT | DISCLAIMER | COLOPHON |
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SUDO(8) BSD System Manager's Manual SUDO(8)
sudo, sudoedit — execute a command as another user
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] [-T timeout] [-u user] [VAR=value]
[-i | -s] [command [arg ...]]
sudoedit [-ABkNnS] [-C num] [-D directory] [-g group] [-h host]
[-p prompt] [-R directory] [-T timeout] [-u user] file ...
sudo allows a permitted user to execute a command as the superuser
or another 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 required, 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 5 minutes.
Security policies may support credential caching to allow the user
to run sudo again for a period of time without requiring
authentication. By default, the sudoers policy caches credentials
on a per-terminal basis for 5 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
privileges, 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
attempts 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 executing a command. The security
policy may restrict the user's ability 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 directory.
-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 environment. 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
temporary 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 security 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 installed. 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 database 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
variable to the home directory specified by the target
user's password 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 currently 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 attempts 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 session; 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 entered 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
credentials 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 require 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
policy, 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 message 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 requested (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 specified)
%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 variable. On systems that use PAM, the custom
prompt will also override 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.
-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 (‘\’) except 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.
-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 timeouts. 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
policies 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 5 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.
Subsequent options are passed to the command.
Options that take a value may only be specified once unless
otherwise indicated 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 options 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 policy subjects environment variables passed as options to
the same restrictions 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.
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)
• 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 security 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 itself 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 terminal 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 receiving 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. This mode is the default for sudo versions
1.9.14 and above when using the sudoers policy.
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 define 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. This
mode is the default for sudo versions prior to 1.9.14 when using
the sudoers policy.
On systems that use PAM, the security policy's close function is
responsible 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 signal 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, however, 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
interposes 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 architecture.
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 terminated 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 successfully (as required by the security policy).
If a command is specified 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
problem, 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.
sudo tries to be safe when executing external commands.
To prevent command spoofing, sudo checks "." and "" (both denoting
current 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 unchanged 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 disables 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.
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 option 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 specified 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 option is specified, when the set_logname
option is enabled in sudoers, or when the
env_reset option is enabled 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 potential 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 being 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.
/etc/sudo.conf sudo front-end configuration
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 redirection to work.
$ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
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 arbitrary 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 information.
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’ option 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 system the sudo binary is located on is mounted
with the ‘nosuid’ option 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
specified 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
characters. This may happen if no terminal is available (or
the -S option 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 specified either via the sudo.conf(5)
file or the SUDO_ASKPASS environment 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 possible 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.
su(1), stat(2), login_cap(3), passwd(5), sudo.conf(5),
sudo_plugin(5), sudoers(5), sudoers_timestamp(5), sudoreplay(8),
visudo(8)
See the HISTORY.md file in the sudo distribution
(https://www.sudo.ws/about/history/) for a brief history of sudo.
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
people who have contributed to sudo.
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 prevent 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).
If you believe you have found a bug in sudo, you can submit a bug
report at https://bugzilla.sudo.ws/
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.
sudo is provided “AS IS” and any express or implied warranties,
including, but not limited to, the implied warranties of
merchantability and fitness for a particular purpose are
disclaimed. See the LICENSE.md file distributed with sudo or
https://www.sudo.ws/about/license/ for complete details.
This page is part of the sudo (execute a command as another user)
project. Information about the project can be found at
https://www.sudo.ws/. If you have a bug report for this manual
page, see ⟨https://bugzilla.sudo.ws/⟩. This page was obtained from
the project's upstream Git repository
⟨https://github.com/sudo-project/sudo⟩ on 2023-06-23. (At that
time, the date of the most recent commit that was found in the
repository was 2023-06-21.) If you discover any rendering problems
in this HTML version of the page, or you believe there is a better
or more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
Sudo 1.9.14 June 18, 2023 Sudo 1.9.14
Pages that refer to this page: journalctl(1), localectl(1), loginctl(1), machinectl(1), portablectl(1), setpriv(1), systemctl(1), systemd(1), systemd-analyze(1), systemd-ask-password(1), systemd-inhibit(1), systemd-nspawn(1), timedatectl(1), userdbctl(1), nsswitch.conf(5), credentials(7), systemd-tmpfiles(8)
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HTML rendering created 2023-06-24 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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