Updated pam_smb packages are now available which fix a security vulnerability (buffer overflow).
The pam_smb module is a pluggable authentication module (PAM) used to authenticate users using an external Server Message Block (SMB) server. A buffer overflow vulnerability has been found that affects unpatched versions of pam_smb up to and including 1.1.6. On systems that use pam_smb and are configured to authenticate a remotely accessible service, an attacker can exploit this bug and remotely execute arbitrary code. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2003-0686 to this issue. CentOS Linux contains a version of pam_smb that is vulnerable to this issue, however pam_smb is not enabled by default. Users of pam_smb are advised to upgrade to these erratum packages, which contain a patch to version 1.1.6 to correct this issue. CentOS would like to thank Dave Airlie of the Samba team for notifying us of this issue.