nss - security update

Antoine Delignat-Lavaud from Inria discovered an issue in the way NSS
(the Mozilla Network Security Service library) was parsing ASN.1 data
used in signatures, making it vulnerable to a signature forgery attack.

An attacker could craft ASN.1 data to forge RSA certificates with a
valid certification chain to a trusted CA.

This update fixes this issue for the NSS libraries.

Note that iceweasel, which is also affected by CVE-2014-1568, however
has reached end-of-life in Squeeze(-LTS) and thus has not been fixed.

For Debian 6 Squeeze, these issues have been fixed in nss version 3.12.8-1+squeeze9