The update_dimensions function in libavcodec/vp8.c in FFmpeg through 2.8.1, as used in Google Chrome before 46.0.2490.71 and other products, relies on a coefficient-partition count during multi-threaded operation, which allows remote attackers to cause a denial of service (race condition and memory corruption) or possibly have unspecified other impact via a crafted WebM file.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ffmpeg | Ffmpeg | * | 2.8.1 (including) |
| Red Hat Enterprise Linux 6 Supplementary | RedHat | chromium-browser-0:46.0.2490.71-1.el6 | * |
| Chromium-browser | Ubuntu | artful | * |
| Chromium-browser | Ubuntu | bionic | * |
| Chromium-browser | Ubuntu | devel | * |
| Chromium-browser | Ubuntu | precise | * |
| Chromium-browser | Ubuntu | trusty | * |
| Chromium-browser | Ubuntu | upstream | * |
| Chromium-browser | Ubuntu | vivid | * |
| Chromium-browser | Ubuntu | wily | * |
| Chromium-browser | Ubuntu | xenial | * |
| Chromium-browser | Ubuntu | yakkety | * |
| Chromium-browser | Ubuntu | zesty | * |
| Ffmpeg | Ubuntu | upstream | * |
| Ffmpeg | Ubuntu | vivid | * |
| Ffmpeg | Ubuntu | wily | * |
| Libav | Ubuntu | esm-infra-legacy/trusty | * |
| Libav | Ubuntu | trusty | * |
| Libav | Ubuntu | trusty/esm | * |
| Libav | Ubuntu | vivid | * |
| Oxide-qt | Ubuntu | artful | * |
| Oxide-qt | Ubuntu | esm-infra/xenial | * |
| Oxide-qt | Ubuntu | trusty | * |
| Oxide-qt | Ubuntu | upstream | * |
| Oxide-qt | Ubuntu | vivid | * |
| Oxide-qt | Ubuntu | vivid/stable-phone-overlay | * |
| Oxide-qt | Ubuntu | wily | * |
| Oxide-qt | Ubuntu | xenial | * |
| Oxide-qt | Ubuntu | yakkety | * |
| Oxide-qt | Ubuntu | zesty | * |
A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:
A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.