Multiple vulnerabilities in the layout engine for Mozilla Firefox 1.5.x before 1.5.0.12 and 2.x before 2.0.0.4, Thunderbird 1.5.x before 1.5.0.12 and 2.x before 2.0.0.4, and SeaMonkey 1.0.9 and 1.1.2 allow remote attackers to cause a denial of service (crash) via vectors related to dangling pointers, heap corruption, signed/unsigned, and other issues.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.