OpenSSL is a toolkit that implements the Secure Sockets Layer and Transport Layer Security protocols, as well as a full-strength, general purpose cryptography library. It was discovered that OpenSSL would accept ephemeral RSA keys when using non-export RSA cipher suites. A malicious server could make a TLS/SSL client using OpenSSL use a weaker key exchange method. An integer underflow flaw, leading to a buffer overflow, was found in the way OpenSSL decoded malformed Base64-encoded inputs. An attacker able to make an application using OpenSSL decode a specially crafted Base64-encoded input could use this flaw to cause the application to crash. Note: this flaw is not exploitable via the TLS/SSL protocol because the data being transferred is not Base64-encoded. A denial of service flaw was found in the way OpenSSL handled SSLv2 handshake messages. A remote attacker could use this flaw to cause a TLS/SSL server using OpenSSL to exit on a failed assertion if it had both the SSLv2 protocol and EXPORT-grade cipher suites enabled. Multiple flaws were found in the way OpenSSL parsed X.509 certificates. An attacker could use these flaws to modify an X.509 certificate to produce a certificate with a different fingerprint without invalidating its signature, and possibly bypass fingerprint-based blacklisting in applications. An out-of-bounds write flaw was found in the way OpenSSL reused certain ASN.1 structures. A remote attacker could possibly use a specially crafted ASN.1 structure that, when parsed by an application, would cause that application to crash. A NULL pointer dereference flaw was found in OpenSSL"s X.509 certificate handling implementation. A specially crafted X.509 certificate could cause an application using OpenSSL to crash if the application attempted to convert the certificate to a certificate request. A NULL pointer dereference was found in the way OpenSSL handled certain PKCS#7 inputs. An attacker able to make an application using OpenSSL verify, decrypt, or parse a specially crafted PKCS#7 input could cause that application to crash. TLS/SSL clients and servers using OpenSSL were not affected by this flaw. Red Hat would like to thank the OpenSSL project for reporting CVE-2015-0287, CVE-2015-0288, CVE-2015-0289, CVE-2015-0292, and CVE-2015-0293. Upstream acknowledges Emilia Kasper of the OpenSSL development team as the original reporter of CVE-2015-0287, Brian Carpenter as the original reporter of CVE-2015-0288, Michal Zalewski of Google as the original reporter of CVE-2015-0289, Robert Dugal and David Ramos as the original reporters of CVE-2015-0292, and Sean Burford of Google and Emilia Kasper of the OpenSSL development team as the original reporters of CVE-2015-0293. 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.