Mozilla Foundation Security Advisory 2015-123

Buffer overflow during image interactions in canvas

Announced
November 3, 2015
Reporter
Looben Yang
Impact
High
Products
Firefox, Firefox ESR, Thunderbird
Fixed in
  • Firefox 42
  • Firefox ESR 38.4
  • Thunderbird 38.4

Description

Security researcher Looben Yang reported a buffer overflow in the JPEGEncoder function during script interactions with a canvas element. This is caused by a race condition and incorrectly matched sizes following image interactions. This leads to a potentially exploitable crash.

In general this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled, but is potentially a risk in browser or browser-like contexts.

References