openssl vulnerabilities

Praveen Kariyanahalli, Ivan Fratric and Felix Groebert discovered that
OpenSSL incorrectly handled memory when buffering DTLS data. A remote
attacker could use this issue to cause OpenSSL to crash, resulting in a
denial of service, or possibly execute arbitrary code. (CVE-2014-8176)

Joseph Barr-Pixton discovered that OpenSSL incorrectly handled malformed
ECParameters structures. A remote attacker could use this issue to cause
OpenSSL to hang, resulting in a denial of service. (CVE-2015-1788)

Robert Swiecki and Hanno Böck discovered that OpenSSL incorrectly handled
certain ASN1_TIME strings. A remote attacker could use this issue to cause
OpenSSL to crash, resulting in a denial of service. (CVE-2015-1789)

Michal Zalewski discovered that OpenSSL incorrectly handled missing content
when parsing ASN.1-encoded PKCS#7 blobs. A remote attacker could use this
issue to cause OpenSSL to crash, resulting in a denial of service.
(CVE-2015-1790)

Emilia Käsper discovered that OpenSSL incorrectly handled NewSessionTicket
when being used by a multi-threaded client. A remote attacker could use
this issue to cause OpenSSL to crash, resulting in a denial of service.
(CVE-2015-1791)

Johannes Bauer discovered that OpenSSL incorrectly handled verifying
signedData messages using the CMS code. A remote attacker could use this
issue to cause OpenSSL to hang, resulting in a denial of service.
(CVE-2015-1792)

As a security improvement, this update also modifies OpenSSL behaviour to
reject DH key sizes below 768 bits, preventing a possible downgrade
attack.