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 NULL pointer derefernce flaw was found in the way OpenSSL verified signatures using the RSA PSS algorithm. A remote attacked could possibly use this flaw to crash a TLS/SSL client using OpenSSL, or a TLS/SSL server using OpenSSL if it enabled client authentication. (CVE-2015-3194)
A memory leak vulnerability was found in the way OpenSSL parsed PKCS#7 and CMS data. A remote attacker could use this flaw to cause an application that parses PKCS#7 or CMS data from untrusted sources to use an excessive amount of memory and possibly crash. (CVE-2015-3195)
A race condition flaw, leading to a double free, was found in the way OpenSSL handled pre-shared key (PSK) identify hints. A remote attacker could use this flaw to crash a multi-threaded SSL/TLS client using OpenSSL. (CVE-2015-3196)
All openssl users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.