Download Firefox

Firefox is no longer supported on Windows 8.1 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox is no longer supported on macOS 10.14 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox Privacy Notice

Mozilla Foundation Security Advisory 2015-138

Use-after-free in WebRTC when datachannel is used after being destroyed

Announced
December 15, 2015
Reporter
Looben Yang
Impact
Critical
Products
Firefox, Firefox ESR, Firefox OS
Fixed in
  • Firefox 43
  • Firefox ESR 38.5
  • Firefox OS 2.5

Description

Security researcher Looben Yang reported a use-after-free error in WebRTC that occurs due to timing issues in WebRTC when closing channels. WebRTC may still believe is has a datachannel open after another WebRTC function has closed it. This results in attempts to use the now destroyed datachannel, leading to a potentially exploitable crash.

References