VISUDO(1m) System Manager's Manual VISUDO(1m) NNAAMMEE vviissuuddoo - edit the sudoers file SSYYNNOOPPSSIISS vviissuuddoo [--cchhqqssVV] [[--ff] _s_u_d_o_e_r_s] DDEESSCCRRIIPPTTIIOONN vviissuuddoo edits the _s_u_d_o_e_r_s file in a safe fashion, analogous to vipw(1m). vviissuuddoo locks the _s_u_d_o_e_r_s file against multiple simultaneous edits, provides basic sanity checks, and checks for parse errors. If the _s_u_d_o_e_r_s file is currently being edited you will receive a message to try again later. vviissuuddoo parses the _s_u_d_o_e_r_s file after editing and will not save the changes if there is a syntax error. Upon finding an error, vviissuuddoo will print a message stating the line number(s) where the error occurred and the user will receive the "What now?" prompt. At this point the user may enter `e' to re-edit the _s_u_d_o_e_r_s file, `x' to exit without saving the changes, or `Q' to quit and save changes. The `Q' option should be used with extreme caution because if vviissuuddoo believes there to be a parse error, so will ssuuddoo and no one will be able to run ssuuddoo again until the error is fixed. If `e' is typed to edit the _s_u_d_o_e_r_s file after a parse error has been detected, the cursor will be placed on the line where the error occurred (if the editor supports this feature). There are two _s_u_d_o_e_r_s settings that determine which editor vviissuuddoo will run. editor A colon (`:') separated list of editors allowed to be used with vviissuuddoo. vviissuuddoo will choose the editor that matches the user's SUDO_EDITOR, VISUAL or EDITOR environment variable if possible, or the first editor in the list that exists and is executable. Note that the SUDO_EDITOR, VISUAL and EDITOR environment variables are not preserved by default when the _e_n_v___r_e_s_e_t _s_u_d_o_e_r_s option is enabled. The default editor path is _v_i which can be set at compile time via the --with-editor configure option. env_editor If set, vviissuuddoo will use the value of the SUDO_EDITOR, VISUAL or EDITOR environment variables before falling back on the default editor list. Note that this may create a security 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 _e_d_i_t_o_r variable. vviissuuddoo will then only use SUDO_EDITOR, VISUAL or EDITOR if they match a value specified in _e_d_i_t_o_r. If the _e_n_v___r_e_s_e_t flag is enabled, the SUDO_EDITOR, VISUAL and/or EDITOR environment variables must be present in the _e_n_v___k_e_e_p list for the _e_n_v___e_d_i_t_o_r flag to function when vviissuuddoo is invoked via ssuuddoo. The default value is _o_f_f, which can be set at compile time via the --with-env-editor configure option. The options are as follows: --cc, ----cchheecckk Enable _c_h_e_c_k_-_o_n_l_y mode. The existing _s_u_d_o_e_r_s file (and any other files it includes) will be checked for syntax errors. If the path to the _s_u_d_o_e_r_s file was not specified, vviissuuddoo will also check the file owner and mode. A message will be printed to the standard output describing the status of _s_u_d_o_e_r_s unless the --qq option was specified. If the check completes successfully, vviissuuddoo will exit with a value of 0. If an error is encountered, vviissuuddoo will exit with a value of 1. --ff _s_u_d_o_e_r_s, ----ffiillee=_s_u_d_o_e_r_s Specify an alternate _s_u_d_o_e_r_s file location, see below. As of version 1.8.27, the _s_u_d_o_e_r_s path can be specified without using the --ff option. --hh, ----hheellpp Display a short help message to the standard output and exit. --qq, ----qquuiieett Enable _q_u_i_e_t mode. In this mode details about syntax errors are not printed. This option is only useful when combined with the --cc option. --ss, ----ssttrriicctt Enable _s_t_r_i_c_t checking of the _s_u_d_o_e_r_s file. If an alias is referenced but not actually defined or if there is a cycle in an alias, vviissuuddoo will consider this a parse error. Note that it is not possible to differentiate between an alias and a host name or user name that consists solely of uppercase letters, digits, and the underscore (`_') character. --VV, ----vveerrssiioonn Print the vviissuuddoo and _s_u_d_o_e_r_s grammar versions and exit. A _s_u_d_o_e_r_s file may be specified instead of the default, _/_e_t_c_/_s_u_d_o_e_r_s. The lock file used is the specified _s_u_d_o_e_r_s file with ".tmp" appended to it. In _c_h_e_c_k_-_o_n_l_y mode only, `-' may be used to indicate that _s_u_d_o_e_r_s will be read from the standard input. Because the policy is evaluated in its entirety, it is not sufficient to check an individual _s_u_d_o_e_r_s include file for syntax errors. DDeebbuuggggiinngg aanndd ssuuddooeerrss pplluuggiinn aarrgguummeennttss vviissuuddoo versions 1.8.4 and higher support a flexible debugging framework that is configured via Debug lines in the sudo.conf(4) file. Starting with ssuuddoo 1.8.12, vviissuuddoo will also parse the arguments to the _s_u_d_o_e_r_s plugin to override the default _s_u_d_o_e_r_s path name, UID, GID and file mode. These arguments, if present, should be listed after the path to the plugin (i.e., after _s_u_d_o_e_r_s_._s_o). Multiple arguments may be specified, separated by white space. For example: Plugin sudoers_policy sudoers.so sudoers_mode=0400 The following arguments are supported: sudoers_file=pathname The _s_u_d_o_e_r_s___f_i_l_e argument can be used to override the default path to the _s_u_d_o_e_r_s file. sudoers_uid=uid The _s_u_d_o_e_r_s___u_i_d argument can be used to override the default owner of the sudoers file. It should be specified as a numeric user ID. sudoers_gid=gid The _s_u_d_o_e_r_s___g_i_d argument can be used to override the default group of the sudoers file. It must be specified as a numeric group ID (not a group name). sudoers_mode=mode The _s_u_d_o_e_r_s___m_o_d_e argument can be used to override the default file mode for the sudoers file. It should be specified as an octal value. For more information on configuring sudo.conf(4), please refer to its manual. EENNVVIIRROONNMMEENNTT The following environment variables may be consulted depending on the value of the _e_d_i_t_o_r and _e_n_v___e_d_i_t_o_r _s_u_d_o_e_r_s settings: SUDO_EDITOR Invoked by vviissuuddoo as the editor to use VISUAL Used by vviissuuddoo if SUDO_EDITOR is not set EDITOR Used by vviissuuddoo if neither SUDO_EDITOR nor VISUAL is set FFIILLEESS _/_e_t_c_/_s_u_d_o_._c_o_n_f Sudo front end configuration _/_e_t_c_/_s_u_d_o_e_r_s List of who can run what _/_e_t_c_/_s_u_d_o_e_r_s_._t_m_p Lock file for visudo DDIIAAGGNNOOSSTTIICCSS In addition to reporting _s_u_d_o_e_r_s parse errors, vviissuuddoo may produce the following messages: sudoers file busy, try again later. Someone else is currently editing the _s_u_d_o_e_r_s file. /etc/sudoers.tmp: Permission denied You didn't run vviissuuddoo as root. you do not exist in the passwd database Your user ID does not appear in the system passwd database. Warning: {User,Runas,Host,Cmnd}_Alias referenced but not defined Either you are trying to use an undeclared {User,Runas,Host,Cmnd}_Alias or you have a user or host name listed that consists solely of uppercase letters, digits, and the underscore (`_') character. In the latter case, you can ignore the warnings (ssuuddoo will not complain). The message is prefixed with the path name of the _s_u_d_o_e_r_s file and the line number where the undefined alias was used. In --ss (strict) mode these are errors, not warnings. Warning: unused {User,Runas,Host,Cmnd}_Alias The specified {User,Runas,Host,Cmnd}_Alias was defined but never used. The message is prefixed with the path name of the _s_u_d_o_e_r_s file and the line number where the unused alias was defined. You may wish to comment out or remove the unused alias. Warning: cycle in {User,Runas,Host,Cmnd}_Alias The specified {User,Runas,Host,Cmnd}_Alias includes a reference to itself, either directly or through an alias it includes. The message is prefixed with the path name of the _s_u_d_o_e_r_s file and the line number where the cycle was detected. This is only a warning unless vviissuuddoo is run in --ss (strict) mode as ssuuddoo will ignore cycles when parsing the _s_u_d_o_e_r_s file. unknown defaults entry "name" The _s_u_d_o_e_r_s file contains a Defaults setting not recognized by vviissuuddoo. SSEEEE AALLSSOO vi(1), sudo.conf(4), sudoers(4), sudo(1m), vipw(1m) AAUUTTHHOORRSS Many people have worked on ssuuddoo over the years; this version consists of code written primarily by: Todd C. Miller See the CONTRIBUTORS file in the ssuuddoo distribution (https://www.sudo.ws/contributors.html) for an exhaustive list of people who have contributed to ssuuddoo. CCAAVVEEAATTSS There is no easy way to prevent a user from gaining a root shell if the editor used by vviissuuddoo allows shell escapes. BBUUGGSS If you feel you have found a bug in vviissuuddoo, please submit a bug report at https://bugzilla.sudo.ws/ SSUUPPPPOORRTT 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. DDIISSCCLLAAIIMMEERR vviissuuddoo 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 file distributed with ssuuddoo or https://www.sudo.ws/license.html for complete details. Sudo 1.8.26 December 24, 2018 Sudo 1.8.26