Mozilla Foundation Security Advisory 2011-35

Additional protection against fraudulent DigiNotar certificates

September 6, 2011
Firefox, Firefox Mobile, SeaMonkey, Thunderbird
Fixed in
  • Firefox 3.6.22
  • Firefox 6.0.2
  • Firefox Mobile 6.0.2
  • SeaMonkey 2.3.3
  • Thunderbird 3.1.14
  • Thunderbird 6.0.2

Description: As more information has come to light about the attack on the DigiNotar Certificate Authority we have improved the protections added in MFSA 2011-34. The main change is to add explicit distrust to the DigiNotar root certificate and several intermediates. Removing the root as in our previous fix meant the certificates could be considered valid if cross-signed by another Certificate Authority. Importantly this list of distrusted certificates includes the "PKIOverheid" (PKIGovernment) intermediates under DigiNotar's control that did not chain to DigiNotar's root and were not previously blocked.