Red Hat: RHSA-2011:0235-01 Important: openssl Security Vulnerability

The GnuTLS library provides support for cryptographic algorithms and for protocols such as Transport Layer Security (TLS).
A flaw was found in the way the TLS/SSL (Transport Layer Security/Secure Sockets Layer) protocols handled session renegotiation. A man-in-the-middle attacker could use this flaw to prefix arbitrary plain text to a client's session (for example, an HTTPS connection to a website). This could force the server to process an attacker's request as if authenticated using the victim's credentials. This update addresses this flaw by implementing the TLS Renegotiation Indication Extension, as defined in RFC 5746. (CVE-2009-3555)
Refer to the following Knowledgebase article for additional details about the CVE-2009-3555 flaw: A flaw was found in the way GnuTLS extracted serial numbers from X.509 certificates. On 64-bit big endian platforms, this flaw could cause the certificate revocation list (CRL) check to be bypassed; cause various GnuTLS utilities to crash; or, possibly, execute arbitrary code. (CVE-2010-0731)
Users of GnuTLS are advised to upgrade to these updated packages, which contain backported patches to correct these issues. For the update to take effect, all applications linked to the GnuTLS library must be restarted, or the system rebooted.