util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy mount(2) path is used without /proc, restricted non-root mount requests validate an /etc/fstab target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab user or users entry whose target has an attacker-writable ancestor can use renameat2(RENAME_EXCHANGE) to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over /etc/sudoers.d, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through /proc/self/fd; the documented legacy fallback without /proc remains affected.
Weakness
The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Util-linux | Ubuntu | jammy | * |
| Util-linux | Ubuntu | noble | * |
| Util-linux | Ubuntu | questing | * |
| Util-linux | Ubuntu | resolute | * |
| Util-linux | Ubuntu | stonking | * |
| Util-linux | Ubuntu | upstream | * |
Potential Mitigations
Related Attack Patterns
References
- https://github.com/util-linux/util-linux/commit/0b010025a0e429bc80355c94db86a843395d49e2
- https://github.com/util-linux/util-linux/commit/0d3d55975aa3492c62fd345eac38f41cd166c0b0
- https://github.com/util-linux/util-linux/commit/2c773f336134acf016e639abb6f12ba7341fe4b8
- https://github.com/util-linux/util-linux/commit/39fef62bf3226abb6bb018fa8750afa0327e84b4
- https://github.com/util-linux/util-linux/commit/472cc3fb2d4d47cca7aab2e0b59eb3fb8a9359ec
- https://github.com/util-linux/util-linux/commit/646fb66603d10a7ac337e14f566f1af48e3107c9
- https://github.com/util-linux/util-linux/commit/708d1b3c51932dc5ba8082c7368187715e6a8d78
- https://github.com/util-linux/util-linux/commit/78a860982e036f38fe9c0b3344998df5ac2c2ff5
- https://github.com/util-linux/util-linux/commit/85d16b341f7232c9dbb4884b632e1e956584bee9
- https://github.com/util-linux/util-linux/commit/a9508d216eb8977979102782672e0470cc9bf2a2
- https://github.com/util-linux/util-linux/releases/tag/v2.41.5
- https://github.com/util-linux/util-linux/releases/tag/v2.42.2
- https://github.com/util-linux/util-linux/releases/tag/v2.42.4
- https://github.com/util-linux/util-linux/security/advisories/GHSA-8gj5-72r3-428g