containerd: Arbitrary host CRI log file read via symlink following in CRI checkpoint restore

containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a bug where the CRI plugin restores container.log from a checkpoint image without validating a symlinked path. This could result in reading an arbitrary file on the host via kubectl logs. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a bug where the CRI plugin restores container.log from a checkpoint image without validating a symlinked path. This could result in reading an arbitrary file on the host via kubectl logs. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a bug where the CRI plugin restores container.log from a checkpoint image without validating a symlinked path. This could result in reading an arbitrary file on the host via kubectl logs. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

### Impact A bug was found in containerd where the CRI plugin restores `container.log` from a checkpoint image without validating a symlinked path. This could result in reading an arbitrary file on the host via `kubectl logs`. ### Patches This bug has been fixed in the following containerd versions: * 2.3.2 * 2.2.5 * 2.1.9 Users should update to these versions to resolve the issue. ### Workarounds Ensure that only trusted images and checkpoints are used. ### Credits The containerd project would like to thank @gouldnicholas and @davidrxchester, Yuming Zhang and Song Li of Zhejiang University, Sangwon Ryu (@sangwon090), Henry Beberman (@hbeberman) of Microsoft, the GKE Security Team using Gemini, Anthropic Research, in collaboration with Claude, Robert Prast (@robertprast), Kyle Elliott (@kyle-elliott-tob) of Trail of Bits, and Zhenchen Wang (@Plucky923), who independently discovered and responsibly disclosed this issue in accordance with the [containerd security policy](https://github.com/containerd/project/blob/main/SECURITY.md). ### For more information If you have any questions or comments about this advisory: * Open an issue in [containerd](https://github.com/containerd/containerd/issues/new/choose) * Email us at [[email protected]](mailto:[email protected]) To report a security issue in containerd: * [Report a new vulnerability](https://github.com/containerd/containerd/security/advisories/new) * Email us at [[email protected]](mailto:[email protected])

Arbitrary host CRI log file read via symlink following in CRI checkpoint restore in github.com/containerd/containerd