The Web Worker functionality in Mozilla Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8, and SeaMonkey before 2.0.3, does not properly handle array data types for posted messages, which allows remote attackers to cause a denial of service (heap memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors.
Weaknesses in this category are related to improper management of system resources.