Writing to cycle collected object during image decoding
- October 29, 2013
- Ezra Pool
- Firefox, Firefox ESR, SeaMonkey, Thunderbird
- Fixed in
- Firefox 25
- Firefox ESR 24.1
- SeaMonkey 2.22
- Thunderbird 24.1
Mozilla community member Ezra Pool reported a potentially exploitable crash on extremely large pages. This was caused when a cycle collected image object was released on the wrong thread during decoding, creating a race condition.
In general this flaw cannot be exploited through email in the Thunderbird and Seamonkey products because scripting is disabled, but is potentially a risk in browser or browser-like contexts.