SELinux PAM: Local password guessing attack — GLSA 200510-22

A vulnerability in the SELinux version of PAM allows a local attacker to brute-force system passwords.

Affected Packages

sys-libs/pam on all architectures
Affected versions < 0.78-r3
Unaffected versions >= 0.78-r3

Background

PAM (Pluggable Authentication Modules) is an architecture allowing the separation of the development of privilege granting software from the development of secure and appropriate authentication schemes. SELinux is an operating system based on Linux which includes Mandatory Access Control.

Description

The SELinux patches for PAM introduce a vulnerability allowing a password to be checked with the unix_chkpwd utility without delay or logging. This vulnerability doesn't affect users who do not run SELinux.

Impact

A local attacker could exploit this vulnerability to brute-force passwords and escalate privileges on an SELinux system.

Workaround

There is no known workaround at this time.

Resolution

All SELinux PAM users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-libs/pam-0.78-r3"

References

Release Date
October 28, 2005

Latest Revision
October 28, 2005: 01

Severity
normal

Exploitable
local

Bugzilla entries