js/src/jstracer.cpp in the browser engine in Mozilla Firefox 3.6.x before 3.6.7 and Thunderbird 3.1.x before 3.1.1 allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors related to (1) propagation of deep aborts in the TraceRecorder::record_JSOP_BINDNAME function, (2) depth handling in the TraceRecorder::record_JSOP_GETELEM function, and (3) tracing of out-of-range arguments in the TraceRecorder::record_JSOP_ARGSUB function.
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.