An updated mod_nss package that fixes one security issue is now available for Red Hat Enterprise Linux 5 and 6. The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System base score, which gives a detailed severity rating, is available from the CVE link in the References section. The mod_nss module provides strong cryptography for the Apache HTTP Server via the Secure Sockets Layer and Transport Layer Security protocols, using the Network Security Services security library. A flaw was found in the way mod_nss handled the NSSVerifyClient setting for the per-directory context. When configured to not require a client certificate for the initial connection and only require it for a specific directory, mod_nss failed to enforce this requirement and allowed a client to access the directory when no valid client certificate was provided. Red Hat would like to thank Albert Smith of OUSD for reporting this issue. All mod_nss users should upgrade to this updated package, which contains a backported patch to correct this issue. The httpd service must be restarted for this update to take effect.