The PreserveWrapper implementation in Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before 17.0.7 does not properly handle the lack of a wrapper, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code by leveraging unintended clearing of the wrapper cache's preserved-wrapper flag.
The XrayWrapper implementation in Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before 17.0.7 does not properly restrict use of DefaultValue for method calls, which allows remote attackers to execute arbitrary JavaScript code with chrome privileges via a crafted web site that triggers use of a user-defined (1) toString or (2) valueOf method.
The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for remote attackers to conduct plaintext-recovery attacks via statistical analysis of ciphertext in a large number of sessions that use the same plaintext.