Depending on the way the format strings in the card label are crafted its possible to leak kernel stack memory. There is also the possibility for DoS due to the v4l2loopback kernel module crashing when providing the card label on request (reproduce e.g. with many %s modifiers in a row).
Weakness
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| V4l2loopback | V4l2loopback_project | * | 0.12.6 (excluding) |
| V4l2loopback | Ubuntu | bionic | * |
| V4l2loopback | Ubuntu | focal | * |
| V4l2loopback | Ubuntu | kinetic | * |
| V4l2loopback | Ubuntu | lunar | * |
| V4l2loopback | Ubuntu | mantic | * |
| V4l2loopback | Ubuntu | oracular | * |
| V4l2loopback | Ubuntu | plucky | * |
| V4l2loopback | Ubuntu | trusty | * |
| V4l2loopback | Ubuntu | xenial | * |
Potential Mitigations
Related Attack Patterns
References
- https://github.com/umlaeute/v4l2loopback/commit/e4cd225557486c420f6a34411f98c575effd43dd
- https://huntr.dev/bounties/1b055da5-7a9e-4409-99d7-030280d242d5
- https://github.com/umlaeute/v4l2loopback/commit/e4cd225557486c420f6a34411f98c575effd43dd
- https://huntr.dev/bounties/1b055da5-7a9e-4409-99d7-030280d242d5