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 product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.