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

http://security.gentoo.org/

Severity:	normal
Title:	SELinux PAM: Local password guessing attack
Date:	10/28/2005
Bugs:	#109485
ID:	200510-22

Synopsis

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

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.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
sys-libs/pam	< 0.78-r3	>= 0.78-r3	All supported architectures

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

CVE-2005-2977

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200510-22.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.