Red Hat: RHSA-2013-1144-01 Moderate: NSS Update Critical Security Issues

Network Security Services (NSS) is a set of libraries designed to support the cross-platform development of security-enabled client and server applications. Netscape Portable Runtime (NSPR) provides platform independence for non-GUI operating system facilities. nss-softokn provides an NSS softoken cryptographic module.
It was discovered that NSS leaked timing information when decrypting TLS/SSL and DTLS protocol encrypted records when CBC-mode cipher suites were used. A remote attacker could possibly use this flaw to retrieve plain text from the encrypted packets by using a TLS/SSL or DTLS server as a padding oracle. (CVE-2013-1620)
An out-of-bounds memory read flaw was found in the way NSS decoded certain certificates. If an application using NSS decoded a malformed certificate, it could cause the application to crash. (CVE-2013-0791)
Red Hat would like to thank the Mozilla project for reporting CVE-2013-0791. Upstream acknowledges Ambroz Bizjak as the original reporter of CVE-2013-0791.
This update also fixes the following bugs:
* The RHBA-2013:0445 update (which upgraded NSS to version 3.14) prevented the use of certificates that have an MD5 signature. This caused problems in certain environments. With this update, certificates that have an MD5 signature are once again allowed. To prevent the use of certificates that have an MD5 signature, set the "NSS_HASH_ALG_SUPPORT" environment variable to "-MD5". (BZ#957603)
* Previously, the sechash.h header file was missing, preventing certain source RPMs (such as firefox and xulrunner) from building. (BZ#948715)
* A memory leak in the nssutil_ReadSecmodDB() function has been fixed. (BZ#984967)
In addition, the nss package has been upgraded to upstream version 3.14.3, the nss-util package has been upgraded to upstream version 3.14.3, the nss-softokn package has been upgraded to upstream version 3.14.3, and the nspr package has been upgraded to upstream version 4.9.5. These updates provide a number of bug fixes and enhancements over the previous versions. (BZ#927157, BZ#927171, BZ#927158, BZ#927186)
Users of NSS, NSPR, nss-util, and nss-softokn are advised to upgrade to these updated packages, which fix these issues and add these enhancements. After installing this update, applications using NSS, NSPR, nss-util, or nss-softokn must be restarted for this update to take effect.