nss - security update

Several vulnerabilities have been discovered in nss, the Mozilla Network
Security Service library. The Common Vulnerabilities and Exposures project
identifies the following problems:

• CVE-2015-2721
  Karthikeyan Bhargavan discovered that NSS incorrectly handles state
  transitions for the TLS state machine. A man-in-the-middle attacker
  could exploit this flaw to skip the ServerKeyExchange message and
  remove the forward-secrecy property.
• CVE-2015-2730
  Watson Ladd discovered that NSS does not properly perform Elliptical
  Curve Cryptography (ECC) multiplication, allowing a remote attacker
  to potentially spoof ECDSA signatures.

For the oldoldstable distribution (squeeze), these problems have been fixed
in version 3.12.8-1+squeeze12.

We recommend that you upgrade your nss packages.