Sudo Stable Release

Current Stable Release

The current stable release of the sudo 1.9 branch is version 1.9.5p1. For the sudo 1.8 branch, see legacy releases.

For full details of all changes, see the ChangeLog file or view the commit history via mercurial or GitHub


Major changes between version 1.9.5p1 and 1.9.5:

  • Fixed a regression introduced in sudo 1.9.5 where the editor run by sudoedit was set-user-ID root unless SELinux RBAC was in use. The editor is now run with the user's real and effective user-IDs.

Major changes between version 1.9.5 and 1.9.4p2:

  • Fixed a crash introduced in 1.9.4 when running sudo -i as an unknown user. This is related to but distinct from Bug #948.

  • If the lecture_file setting is enabled in sudoers, it must now refer to a regular file or a symbolic link to a regular file.

  • Fixed a potential use-after-free bug in sudo_logsrvd when the server shuts down if there are existing connections from clients that are only logging events and not session I/O data.

  • Fixed a buffer size mismatch when serializing the list of IP addresses for configured network interfaces. This bug is not actually exploitable since the allocated buffer is large enough to hold the list of addresses.

  • If sudo is executed with a name other than sudo or sudoedit, it will now fall back to sudo as the program name. This affects warning, help and usage messages as well as the matching of Debug lines in the /etc/sudo.conf file. Previously, it was possible for the invoking user to manipulate the program name by setting argv[0] to an arbitrary value when executing sudo.

  • Sudo now checks for failure when setting the close-on-exec flag on open file descriptors. This should never fail but, if it were to, there is the possibility of a file descriptor leak to a child process (such as the command sudo runs).

  • Fixed CVE-2021-23239, a potential information leak in sudoedit that could be used to test for the existence of directories not normally accessible to the user in certain circumstances. When creating a new file, sudoedit checks to make sure the parent directory of the new file exists before running the editor. However, a race condition exists if the invoking user can replace (or create) the parent directory. If a symbolic link is created in place of the parent directory, sudoedit will run the editor as long as the target of the link exists. If the target of the link does not exist, an error message will be displayed. The race condition can be used to test for the existence of an arbitrary directory. However, it cannot be used to write to an arbitrary location.

  • Fixed CVE-2021-23240, a flaw in the temporary file handling of sudoedit's SELinux RBAC support. On systems where SELinux is enabled, a user with sudoedit permissions may be able to set the owner of an arbitrary file to the user-ID of the target user. On Linux kernels that support protected symlinks setting /proc/sys/fs/protected_symlinks to 1 will prevent the bug from being exploited. For more information, see Symbolic link attack in SELinux-enabled sudoedit.

  • Added writability checks for sudoedit when SELinux RBAC is in use. This makes sudoedit behavior consistent regardless of whether or not SELinux RBAC is in use. Previously, the sudoedit_checkdir setting had no effect for RBAC entries.

  • A new sudoers option selinux can be used to disable sudo's SELinux RBAC support.

  • Quieted warnings from PVS Studio, clang analyzer, and cppcheck. Added suppression annotations for PVS Studio false positives.

Major changes between version 1.9.4p2 and 1.9.4p1:

  • Fixed a bug introduced in sudo 1.9.4p1 which could lead to a crash if the sudoers file contains a runas user-specific Defaults entry. Bug #951.

Major changes between version 1.9.4p1 and 1.9.4:

  • Sudo on macOS now supports users with more than 16 groups without needing to set group_source to dynamic in sudo.conf. Previously, only the first 15 were used when matching group-based rules in sudoers. Bug #946.

  • Fixed a regression introduced in version 1.9.4 where sudo would not build when configured using the --without-sendmail option. Bug #947.

  • Fixed a problem where if I/O logging was disabled and sudo was unable to connect to sudo_logsrvd, the command would still be allowed to run even when the ignore_logfile_errors sudoers option was enabled.

  • Fixed a crash introduced in version 1.9.4 when attempting to run a command as a non-existent user. Bug #948.

  • The installed sudo.conf file now has the default sudoers Plugin lines commented out. This fixes a potential conflict when there is both a system-installed version of sudo and a user-installed version. GitHub Issue #75.

  • Fixed a regression introduced in sudo 1.9.4 where sudo would run the command as a child process even when a pseudo-terminal was not in use and the pam_session and pam_setcred options were disabled. GitHub Issue #76.

  • Fixed a regression introduced in sudo 1.8.9 where the closefrom sudoers option could not be set to a value of 3. Bug #950.

Major changes between version 1.9.4 and 1.9.3p1:

  • The sudoers parser will now detect when an upper-case reserved word is used when declaring an alias. Now instead of syntax error, unexpected CHROOT, expecting ALIAS the message will be syntax error, reserved word CHROOT used as an alias name. Bug #941.

  • Better handling of sudoers files without a final newline. The parser now adds a newline at end-of-file automatically which removes the need for special cases in the parser.

  • Fixed a regression introduced in sudo 1.9.1 in the sssd back-end where an uninitialized pointer could be freed on an error path. GitHub Issue #67.

  • The core logging code is now shared between sudo_logsrvd and the sudoers plugin.

  • JSON log entries sent to syslog now use minimal JSON which skips all non-essential whitespace.

  • The sudoers plugin can now produce JSON-formatted logs. The log_format sudoers option can be used to select sudo or json format logs. The default is sudo format logs.

  • The sudoers plugin and visudo now display the column number in syntax error messages in addition to the line number. Bug #841.

  • If I/O logging is not enabled but log_servers is set, the sudoers plugin will now log accept events to sudo_logsrvd. Previously, the accept event was only sent when I/O logging was enabled. The sudoers plugin now sends reject and alert events too.

  • The sudo logsrv protocol has been extended to allow an AlertMessage to contain an optional array of InfoMessage, as AcceptMessage and RejectMessage already do.

  • Fixed a bug in sudo_logsrvd where receipt of SIGHUP would result in duplicate entries in the debug log when debugging was enabled.

  • The visudo utility now supports EDITOR environment variables that use single or double quotes in the command arguments. Bug #942.

  • The PAM session modules now run when sudo is set-user-ID root, which allows a module to determine the original user-ID. Bug #944.

  • Fixed a regression introduced in sudo 1.8.24 in the LDAP back-end where sudoNotBefore and sudoNotAfter were applied even when the SUDOERS_TIMED setting was not present in ldap.conf. Bug #945.

  • Sudo packages for macOS 11 now contain universal binaries that support both Intel and Apple Silicon CPUs.

  • For sudo_logsrvd, an empty value for the pid_file setting in sudo_logsrvd.con will now disable the process ID file.

Major changes between version 1.9.3p1 and 1.9.3:

  • Fixed a regression introduced in sudo 1.9.3 where the configure script would not detect the crypt function if it was present in the C library, not an additional library.

  • Fixed a regression introduced in sudo 1.8.23 with shadow passwd file authentication on OpenBSD. BSD authentication was not affected.

  • Sudo now logs when a user-specified command-line option is rejected by a sudoers rule. Previously, these conditions were written to the audit log, but the default sudo log file. Affected command line arguments include -C (--close-from), -D (--chdir), -R (--chroot), -g (--group) and -u (--user).

Major changes between version 1.9.3 and 1.9.2:

  • sudoedit will now prompt the user before overwriting an existing file with one that is zero-length after editing. Bug #922.

  • Fixed building the Python plugin on systems with a compiler that doesn't support symbol hiding.

  • Sudo now uses a linker script to hide symbols even when the compiler has native symbol hiding support. This should make it easier to detect omissions in the symbol exports file, regardless of the platform.

  • Fixed the libssl dependency in Debian packages for older releases that use libssl1.0.0.

  • sudo and visudo now provide more detailed messages when a syntax error is detected in sudoers. The offending line and token are now displayed. If the parser was generated by GNU bison, additional information about what token was expected is also displayed. Bug #841.

  • Sudoers rules must now end in either a newline or the end-of-file. Previously, it was possible to have multiple rules on a single line, separated by white space. The use of an end-of-line terminator makes it possible to display accurate error messages.

  • Sudo no longer refuses to run if a syntax error in the sudoers file is encountered. The entry with the syntax error will be discarded and sudo will continue to parse the file. This makes recovery from a syntax error less painful on systems where sudo is the primary method of superuser access. The historic behavior can be restored by add error_recovery=false to the sudoers plugin's optional arguments in sudo.conf. Bug #618.

  • Fixed the sample_approval plugin's symbol exports file for systems where the compiler doesn't support symbol hiding.

  • Fixed a regression introduced in sudo 1.9.1 where arguments to the sudoers_policy plugin in sudo.conf were not being applied. The sudoers file is now parsed by the sudoers_audit plugin, which is loaded implicitly when sudoers_policy is listed in sudo.conf. Starting with sudo 1.9.3, if there are plugin arguments for sudoers_policy but sudoers_audit is not listed, those arguments will be applied to sudoers_audit instead.

  • The user's resource limits are now passed to sudo plugins in the user_info[] list. A plugin cannot determine the limits itself because sudo changes the limits while it runs to prevent resource starvation.

  • It is now possible to set the working directory or change the root directory on a per-command basis using the CWD and CHROOT options. There are also new Defaults settings, runchroot and runcwd, that can be used to set the working directory or root directory on a more global basis.

  • New -D (--chdir) and -R (--chroot) command line options can be used to set the working directory or root directory if the sudoers file allows it. This functionality is not enabled by default and must be explicitly enabled in the sudoers file.

Major changes between version 1.9.2 and 1.9.1:

  • Fixed package builds on RedHat Enterprise Linux 8.

  • The configure script now uses pkg-config to find the openssl cflags and libs where possible.

  • The contents of the log.json I/O log file is now documented in the sudoers manual.

  • The sudoers plugin now properly exports the sudoers_audit symbol on systems where the compiler lacks symbol visibility controls. This caused a regression in 1.9.1 where a successful sudo command was not logged due to the missing audit plugin. Bug #931.

  • Fixed a regression introduced in 1.9.1 that can result in crash when there is a syntax error in the sudoers file. Bug #934.

Major changes between version 1.9.1 and 1.9.0:

  • Fixed an AIX-specific problem when I/O logging was enabled. The terminal device was not being properly set to raw mode. Bug #927.

  • Corrected handling of sudo_logsrvd connections without associated I/O log data. This fixes support for RejectMessage as well as AcceptMessage when the expect_iobufs flag is not set.

  • Added an iolog_path entry to the JSON-format event log produced by sudo_logsrvd. Previously, it was only possible to determine the I/O log file an event belonged to using sudo-format logs.

  • Fixed the bundle IDs for sudo-logsrvd and sudo-python macOS packages.

  • I/O log files produced by the sudoers plugin now clear the write bits on the I/O log timing file when the log is complete. This is consistent with how sudo_logsrvd indicates that a log is complete.

  • The sudoreplay utility has a new -F (follow) command line option to allow replaying a session that is still in progress, similar to tail -f.

  • The @include and @includedir directives can be used in sudoers instead of #include and #includedir. In addition, include paths may now have embedded white space by either using a double-quoted string or escaping the space characters with a backslash.

  • Fixed some Solaris 11.4 compilation errors.

  • When running a command in a pty, sudo will no longer try to suspend itself if the user's tty has been revoked (for instance when the parent ssh daemon is killed). This fixes a bug where sudo would continuously suspend the command (which would succeed), then suspend itself (which would fail due to the missing tty) and then resume the command.

  • If sudo's event loop fails due to the tty being revoked, remove the user's tty events and restart the event loop (once). This fixes a problem when running sudo reboot in a pty on some systems. When the event loop exited unexpectedly, sudo would kill the command running in the pty, which in the case of reboot, could lead to the system being in a half-rebooted state.

  • Fixed a regression introduced in sudo 1.8.23 in the LDAP and SSSD back-ends where a missing sudoHost attribute was treated as an ALL wildcard value. A sudoRole with no sudoHost attribute is now ignored as it was prior to version 1.8.23.

  • The audit plugin API has been changed slightly. The sudo front-end now audits an accept event itself after all approval plugins are run and the I/O logging plugins (if any) are opened. This makes it possible for an audit plugin to only log a single overall accept event if desired.

  • The sudoers plugin can now be loaded as an audit plugin. Logging of successful commands is now performed in the audit plugin's accept function. As a result, commands are now only logged if allowed by sudoers and all approval plugins. Commands rejected by an approval plugin are now also logged by the sudoers plugin.

  • Romanian translation for sudo and sudoers from translationproject.org.

  • Fixed a regression introduced in sudo 1.9.0 where sudoedit did not remove its temporary files after installing them. Bug #929.

  • Fixed a regression introduced in sudo 1.9.0 where the iolog_file setting in sudoers and sudo_logsrvd.conf caused an error if the file name ended in six or more X's.

Major changes between version 1.9.0 and 1.8.31p1:

  • Fixed a test failure in the strsig_test on FreeBSD.

  • The maximum length of a conversation reply has been increased from 255 to 1023 characters. This allows for longer user passwords. Bug #860.

  • Sudo now includes a logging daemon, sudo_logsrvd, which can be used to implement centralized logging of I/O logs. TLS connections are supported when sudo is configured with the --enable-openssl option. For more information, see the sudo_logsrvd, sudo_logsrvd.conf and sudo_logsrv.proto manuals as well as the log_servers setting in the sudoers manual.

    The --disable-log-server and --disable-log-client configure options can be used to disable building the I/O log server and/or remote I/O log support in the sudoers plugin.

  • The new sudo_sendlog utility can be used to test sudo_logsrvd or send existing sudo I/O logs to a centralized server.

  • It is now possible to write sudo plugins in Python 4 when sudo is configured with the --enable-python option. See the sudo_plugin_python manual for details.

    Sudo 1.9.0 comes with several Python example plugins that get installed sudo's examples directory.

    The sudo blog article What's new in sudo 1.9: Python includes a simple tutorial on writing python plugins.

  • Sudo now supports an audit plugin type. An audit plugin receives accept, reject, exit and error messages and can be used to implement custom logging that is independent of the underlying security policy. Multiple audit plugins may be specified in the sudo.conf file. A sample audit plugin is included that writes logs in JSON format.

  • Sudo now supports an approval plugin type. An approval plugin is run only after the main security policy (such as sudoers) accepts a command to be run. The approval policy may perform additional checks, potentially interacting with the user. Multiple approval plugins may be specified in the sudo.conf file. Only if all approval plugins succeed will the command be allowed.

  • Sudo's -S command line option now causes the sudo conversation function to write to the standard output or standard error instead of the terminal device.

  • Fixed a bug where if a #include or #includedir directive was the last line in sudoers and there was no final newline character, it was silently ignored. Bug #917.

  • It is now possible to use Cmd_Alias instead of Cmnd_Alias in sudoers for people who find the former more natural.

  • The new pam_ruser and pam_rhost sudoers settings can be used to enable or disable setting the PAM remote user and/or host values during PAM session setup.

  • More than one SHA-2 digest may now be specified for a single command. Multiple digests must be separated by a comma.

  • It is now possible to specify a SHA-2 digest in conjunction with the ALL reserved word in a command specification. This allows one to give permission to run any command that matches the specified digest, regardless of its path.

  • sudo and sudo_logsrvd now create an extended I/O log info file in JSON format that contains additional information about the command that was run, such as the host name. The sudoreplay utility uses this file in preference to the legacy log file.

  • The sudoreplay utility can now match on a host name in list mode. The list output also now includes the host name if one is present in the log file.

  • For sudo -i, if the target user's home directory does not exist, sudo will now warn about the problem but run the command in the current working directory. Previously, this was a fatal error. Debian bug #598519.

  • The command line arguments in the SUDO_COMMAND environment variable are now truncated at 4096 characters. This avoids an Argument list too long error when executing a command with a large number of arguments. Bug #923 and Debian bug #596631.

  • Sudo now properly ends the PAM transaction when the user authenticates successfully but sudoers denies the command. Debian bug #669687.

  • The sudoers grammar in the manual now indicates that sudoedit requires one or more arguments. Debian bug #571621.

  • When copying the edited files to the original path, sudoedit now allocates any additional space needed before writing. Previously, it could truncate the destination file if the file system was full. Bug #922.

  • Fixed an issue where PAM session modules could be called with the wrong user name when multiple users in the passwd database share the the same user-ID. Debian bug #734752.

  • Sudo command line options that take a value may only be specified once. This is to help guard against problems caused by poorly written scripts that invoke sudo with user-controlled input. Bug #924.