PAM_GROUP(8) Linux-PAM Manual PAM_GROUP(8)
pam_group - PAM module for group access
The pam_group PAM module does not authenticate the user, but instead it grants group memberships (in the credential setting phase of the authentication module) to the user. Such memberships are based on the service they are applying for. By default rules for group memberships are taken from config file /etc/security/group.conf. This module's usefulness relies on the file-systems accessible to the user. The point being that once granted the membership of a group, the user may attempt to create a setgid binary with a restricted group ownership. Later, when the user is not given membership to this group, they can recover group membership with the precompiled binary. The reason that the file-systems that the user has access to are so significant, is the fact that when a system is mounted nosuid the user is unable to create or execute such a binary file. For this module to provide any level of security, all file-systems that the user has write access to should be mounted nosuid. The pam_group module functions in parallel with the /etc/group file. If the user is granted any groups based on the behavior of this module, they are granted in addition to those entries /etc/group (or equivalent).
This module does not recognise any options.
Only the auth module type is provided.
PAM_SUCCESS group membership was granted. PAM_ABORT Not all relevant data could be gotten. PAM_BUF_ERR Memory buffer error. PAM_CRED_ERR Group membership was not granted. PAM_IGNORE pam_sm_authenticate was called which does nothing. PAM_USER_UNKNOWN The user is not known to the system.
/etc/security/group.conf Default configuration file
group.conf(5), pam.d(5), pam(8).
pam_group was written by Andrew G. Morgan <email@example.com>.
This page is part of the linux-pam (Pluggable Authentication Modules for Linux) project. Information about the project can be found at ⟨http://www.linux-pam.org/⟩. If you have a bug report for this manual page, see ⟨//www.linux-pam.org/⟩. This page was obtained from the project's upstream Git repository ⟨https://github.com/linux-pam/linux-pam.git⟩ on 2023-06-23. (At that time, the date of the most recent commit that was found in the repository was 2023-06-07.) 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 firstname.lastname@example.org Linux-PAM Manual 12/16/2022 PAM_GROUP(8)
Pages that refer to this page: group.conf(5)