WebRTC can use a WrappedI420Buffer pixel buffer but the owning image object can be freed while it is still in use. This can result in the WebRTC encoder using uninitialized memory, leading to a potentially exploitable crash. This vulnerability affects Firefox < 60.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ubuntu_linux | Canonical | 14.04 (including) | 14.04 (including) |
| Ubuntu_linux | Canonical | 16.04 (including) | 16.04 (including) |
| Ubuntu_linux | Canonical | 17.10 (including) | 17.10 (including) |
| Ubuntu_linux | Canonical | 18.04 (including) | 18.04 (including) |
| Firefox | Ubuntu | artful | * |
| Firefox | Ubuntu | bionic | * |
| Firefox | Ubuntu | devel | * |
| Firefox | Ubuntu | trusty | * |
| Firefox | Ubuntu | upstream | * |
| Firefox | Ubuntu | xenial | * |
Potential Mitigations
References
- http://www.securityfocus.com/bid/104139
- http://www.securitytracker.com/id/1040896
- https://bugzilla.mozilla.org/show_bug.cgi?id=1436117
- https://usn.ubuntu.com/3645-1/
- https://www.mozilla.org/security/advisories/mfsa2018-11/
- http://www.securityfocus.com/bid/104139
- http://www.securitytracker.com/id/1040896
- https://bugzilla.mozilla.org/show_bug.cgi?id=1436117
- https://usn.ubuntu.com/3645-1/
- https://www.mozilla.org/security/advisories/mfsa2018-11/