Red Hat: RHSA-2010:0163-01 Moderate: OpenSSL Session Handling Flaws

OpenSSL is a toolkit that implements the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols, as well as a full-strength, general purpose cryptography library.
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: Dan Kaminsky found that browsers could accept certificates with MD2 hash signatures, even though MD2 is no longer considered a cryptographically strong algorithm. This could make it easier for an attacker to create a malicious certificate that would be treated as trusted by a browser. OpenSSL now disables the use of the MD2 algorithm inside signatures by default. (CVE-2009-2409)
An input validation flaw was found in the handling of the BMPString and UniversalString ASN1 string types in OpenSSL's ASN1_STRING_print_ex() function. An attacker could use this flaw to create a specially-crafted X.509 certificate that could cause applications using the affected function to crash when printing certificate contents. (CVE-2009-0590)
Note: The affected function is rarely used. No application shipped with Red Hat Enterprise Linux calls this function, for example.
All OpenSSL users should upgrade to these updated packages, which contain backported patches to resolve these issues. For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.