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 security@containerd.io
To report a security issue in containerd:
Report a new vulnerability
Impact
A bug was found in containerd's CRI Attach implementation where a user can exhaust memory on the host due to goroutine leaks.
Repetitive calls of CRI Attach (e.g., kubectl attach) could increase the memory usage of containerd.
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.
Workarounds
Set up an admission controller to control accesses to pods/attach resources. e.g., Validating Admission Policy.
Credits
The containerd project would like to thank @Wheat2018 for responsibly disclosing this issue in accordance with the containerd security policy.
References
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-64329
For more information
If you have any questions or comments about this advisory:
Open an issue in containerd Email us at security@containerd.io
To report a security issue in containerd:
Report a new vulnerability