gnutls26 vulnerability

USN-3183-1 fixed CVE-2016-8610 in GnuTLS in Ubuntu 16.04 LTS and Ubuntu
16.10. This update provides the corresponding update for Ubuntu 12.04 LTS
and Ubuntu 14.04 LTS.

Original advisory details:

Stefan Buehler discovered that GnuTLS incorrectly verified the serial
length of OCSP responses. A remote attacker could possibly use this issue
to bypass certain certificate validation measures. This issue only applied
to Ubuntu 16.04 LTS. (CVE-2016-7444)

Shi Lei discovered that GnuTLS incorrectly handled certain warning alerts.
A remote attacker could possibly use this issue to cause GnuTLS to hang,
resulting in a denial of service. This issue has only been addressed in
Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-8610)

It was discovered that GnuTLS incorrectly decoded X.509 certificates with a
Proxy Certificate Information extension. A remote attacker could use this
issue to cause GnuTLS to crash, resulting in a denial of service, or
possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS
and Ubuntu 16.10. (CVE-2017-5334)

It was discovered that GnuTLS incorrectly handled certain OpenPGP
certificates. A remote attacker could possibly use this issue to cause
GnuTLS to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2017-5335, CVE-2017-5336, CVE-2017-5337)