Red Hat Enterprise Linux 5 RHSA-2010:0819-01 Moderate: Pam Escalation

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. (CVE-2010-3435)
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. (CVE-2010-3316)
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.