2.1 - RHSA-2005:805

Problem Description:

An updated pam package that fixes a security weakness is now available for Red Hat Enterprise Linux 4.

This update has been rated as having low security impact by the Red Hat Security Response Team.

2. Relevant releases/architectures:

Red Hat Enterprise Linux AS version 4 - i386, ia64, ppc, s390, s390x, x86_64 Red Hat Enterprise Linux Desktop version 4 - i386, x86_64 Red Hat Enterprise Linux ES version 4 - i386, ia64, x86_64 Red Hat Enterprise Linux WS version 4 - i386, ia64, x86_64

3. Problem description:

PAM (Pluggable Authentication Modules) is a system security tool that allows system administrators to set an authentication policy without having to recompile programs that handle authentication.

A bug was found in the way PAM's unix_chkpwd helper program validates user passwords when SELinux is enabled. Under normal circumstances, it is not possible for a local non-root user to verify the password of another local user with the unix_chkpwd command. A patch applied that adds SELinux functionality makes it possible for a local user to use brute force password guessing techniques against other local user accounts. The Common Vulnerabilities and Exposures project has assigned the name CVE-2005-2977 to this issue.

All users of pam should upgrade to this updated package, which contains backported patches to correct these issues.

4. Solution:

Before applying this update, make sure all previously released errata relevant to your system have been applied.

This update is available via Red Hat Network. To use Red Hat Network, launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate RPMs being upgraded on your system.

5. Bug IDs fixed (http://bugzilla.redhat.com/):

168181 - CVE-2005-2977 unix_chkpwd helper doesn't verify requesting user if SELinux is enabled