Ubuntu 23.10: USN-6588-1 Critical PAM Denial of Service

ubuntu

January 17, 2024

PAM could be made to stop responding if it opened a specially crafted file.

Summary

PAM could be made to stop responding if it opened a specially crafted file.

Software Description:

- pam: Pluggable Authentication Modules

Details:

Matthias Gerstner discovered that the PAM pam_namespace module incorrectly

handled special files when performing directory checks. A local attacker

could possibly use this issue to cause PAM to stop responding, resulting in

a denial of service.

Topics Covered

security advisory denial of service update critical Ubuntu pam

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 23.10:
   libpam-modules                  1.5.2-6ubuntu1.1

Ubuntu 23.04:
   libpam-modules                  1.5.2-5ubuntu1.1

Ubuntu 22.04 LTS:
   libpam-modules                  1.4.0-11ubuntu2.4

Ubuntu 20.04 LTS:
   libpam-modules                  1.3.1-5ubuntu4.7

In general, a standard system update will make all the necessary changes.