CentOS 5 : pam (CESA-2010:0819)
Medium Nessus Plugin ID 50804
SynopsisThe remote CentOS host is missing one or more security updates.
DescriptionUpdated pam packages that fix three security issues are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.
Pluggable Authentication Modules (PAM) provide a system whereby administrators can set up authentication policies without having to recompile programs that handle authentication.
It was discovered that the pam_namespace module executed the external script namespace.init with an unchanged environment inherited from an application calling PAM. In cases where such an environment was untrusted (for example, when pam_namespace was configured for setuid applications such as su or sudo), a local, unprivileged user could possibly use this flaw to escalate their privileges. (CVE-2010-3853)
It was discovered that the pam_mail module used root privileges while accessing users' files. In certain configurations, a local, unprivileged user could use this flaw to obtain limited information about files or directories that they do not have access to.
It was discovered that the pam_xauth module did not verify the return values of the setuid() and setgid() system calls. A local, unprivileged user could use this flaw to execute the xauth command with root privileges and make it read an arbitrary input file.
Red Hat would like to thank Sebastian Krahmer of the SuSE Security Team for reporting the CVE-2010-3435 issue.
All pam users should upgrade to these updated packages, which contain backported patches to correct these issues.
SolutionUpdate the affected pam packages.