Ubuntu Security Notice USN-810-1 – Moxie Marlinspike discovered that NSS did not properly handle regular expressions in certificate names. A remote attacker could create a specially crafted certificate to cause a denial of service (via application crash) or execute arbitrary code as the user invoking the program. Moxie Marlinspike and Dan Kaminsky independently discovered that NSS did not properly handle certificates with NULL characters in the certificate name. An attacker could exploit this to perform a man in the middle attack to view sensitive information or alter encrypted communications. Dan Kaminsky discovered NSS would still accept certificates with MD2 hash signatures. As a result, an attacker could potentially create a malicious trusted certificate to impersonate another site.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/80046/USN-810-1.txt
Source: https://packetstormsecurity.com/files/80046/Ubuntu-Security-Notice-810-1.html