Rapid7 Vulnerability & Exploit Database

CESA-2004:304: pam security update

Free InsightVM Trial No credit card necessary
Watch Demo See how it all works
Back to Search

CESA-2004:304: pam security update



Updated pam packages that fix a security vulnerability are now available for CentOS Linux 2.1.

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. These updates fix a potential security problem present in the pam_wheel module. These updates correct a bug in the pam_lastlog module which prevented it from properly manipulating the /var/log/lastlog entry for users with very high user IDs. The pam_wheel module is used to restrict access to a particular service based on group membership. If the pam_wheel module was used with the "trust" option enabled, but without the "use_uid" option, any local user would be able to spoof the username returned by getlogin(). The user could therefore gain access to a superuser account without supplying a password. In CentOS Linux 2.1, pam_wheel is not used by default. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2003-0388 to this issue. When manipulating the entry in /var/log/lastlog, which corresponds to a given user, the pam_lastlog module calculates the location of the entry by multiplying the UID and the length of an entry in the file. On some systems, the result of this calculation would mistakenly be truncated to 32 bits for users with sufficiently high UIDs. All users of pam should upgrade to these updated packages, which resolve these issues.


  • centos-upgrade-pam
  • centos-upgrade-pam-devel

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center