GHSA-pwhc-rpq9-4c8w containerd affected by a local privilege escalation via wide permissions on CRI directory

• Go github.com/containerd/containerd: < 1.7.29 → fixed in 1.7.29 • Go github.com/containerd/containerd/v2: < 2.0.7 → fixed in 2.0.7 • Go github.com/containerd/containerd/v2: >= 2.1.0-beta.0, < 2.1.5 → fixed in 2.1.5 • Go github.com/containerd/containerd/v2: >= 2.2.0-beta.0, < 2.2.0 → fixed in 2.2.0

Impact An overly broad default permission vulnerability was found in containerd. • `/var/lib/containerd` was created with the permission bits 0o711, while it should be created with 0o700 • Allowed local users on the host to potentially access the metadata store and the content store • `/run/containerd/io.containerd.grpc.v1.cri` was created with 0o755, while it should be created with 0o700 • Allowed local users on the host to potentially access the contents of Kubernetes local volumes. The contents of volumes might include setuid binaries, which could allow a local user on the host to elevate privileges on the host. • `/run/containerd/io.containerd.sandbox.controller.v1.shim` was created with 0o711, while it should be created with 0o700 The directory paths may differ depending on the daemon configuration. When the `temp` directory path is specified in the daemon configuration, that directory was also created with 0o711, while it should be created with 0o700. Patches This bug has been fixed in the following containerd versions: • 2.2.0 • 2.1.5 • 2.0.7 • 1.7.29 Users should update to these versions to resolve the issue. These updates automatically change the permissions of the existing directories. > [!NOTE] > > `/run/containerd` and `/run/containerd/io.containerd.runtime.v2.task` are still created with 0o711. > This is an expected behavior for supporting userns-remapped containers. Workarounds The system administrator on the host can manually chmod the directories to not have group or world accessible permisisons: ``` chmod 700 /var/lib/containerd chmod 700 /run/containerd/io.containerd.grpc.v1.cri chmod 700 /run/containerd/io.containerd.sandbox.controller.v1.shim ``` An alternative mitigation would be to run containerd in rootless mode. Credits The containerd project would like to thank David Leadbeater for responsibly disclosing this issue in accordance with the containerd security policy. For more information If you have any questions or comments about this advisory: • Open an issue in containerd • Email us at [email protected] To report a security issue in containerd: • Report a new vulnerability