Ubuntu Security Notice 3029-1 – Tyson Smith and Jed Davis discovered that NSS incorrectly handled memory. A remote attacker could use this issue to cause NSS to crash, resulting in a denial of service, or possibly execute arbitrary code. This update refreshes the NSS package to version 3.23 which includes the latest CA certificate bundle. As a security improvement, this update also modifies NSS behaviour to reject DH key sizes below 1024 bits, preventing a possible downgrade attack. Various other issues were also addressed.