openssl - security update

Multiple vulnerabilities were discovered in OpenSSL, a Secure Sockets
Layer toolkit.

• CVE-2014-8176
  Praveen Kariyanahalli, Ivan Fratric and Felix Groebert discovered
  that an invalid memory free could be triggered when buffering DTLS
  data. This could allow remote attackers to cause a denial of service
  (crash) or potentially execute arbitrary code. This issue only
  affected the oldstable distribution (wheezy).
• CVE-2015-1789
  Robert Swiecki and Hanno BĂśck discovered that the X509_cmp_time
  function could read a few bytes out of bounds. This could allow remote
  attackers to cause a denial of service (crash) via crafted
  certificates and CRLs.
• CVE-2015-1790
  Michal Zalewski discovered that the PKCS#7 parsing code did not
  properly handle missing content which could lead to a NULL pointer
  dereference. This could allow remote attackers to cause a denial of
  service (crash) via crafted ASN.1-encoded PKCS#7 blobs.
• CVE-2015-1791
  Emilia Käsper discovered that a race condition could occur due to
  incorrect handling of NewSessionTicket in a multi-threaded client,
  leading to a double free. This could allow remote attackers to cause
  a denial of service (crash).
• CVE-2015-1792
  Johannes Bauer discovered that the CMS code could enter an infinite
  loop when verifying a signedData message, if presented with an
  unknown hash function OID. This could allow remote attackers to cause
  a denial of service.

Additionally OpenSSL will now reject handshakes using DH parameters
shorter than 768 bits as a countermeasure against the Logjam attack
(CVE-2015-4000).