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