Impact
A bug was found in containerd's CRI implementation where a user can exhaust memory on the host. In the CRI stream server, a goroutine is launched to handle terminal resize events if a TTY is requested. If the user's process fails to launch due to, for example, a faulty command, the goroutine will be stuck waiting to send without a receiver, resulting in a memory leak. Kubernetes and crictl can both be configured to use containerd's CRI implementation and the stream server is used for handling container IO.
Patches
This bug has been fixed in containerd 1.6.12 and 1.5.16. Users should update to these versions to resolve the issue.
Workarounds
Ensure that only trusted images and commands are used and that only trusted users have permissions to execute commands in running containers.
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 Email us at security@containerd.io
Impact
A bug was found in containerd's CRI implementation where programs inside a container can cause the containerd daemon to consume memory without bound during invocation of the ExecSync API. This can cause containerd to consume all available memory on the computer, denying service to other legitimate workloads. Kubernetes and crictl can both be configured to use containerd's CRI implementation; ExecSync may be used when running probes or when executing processes via an "exec" facility.
Patches
This bug has been fixed in containerd 1.6.6 and 1.5.13. Users should update to these versions to resolve the issue.
Workarounds
Ensure that only trusted images and commands are used.
References
Similar fix in cri-o's CRI implementation https://github.com/cri-o/cri-o/security/advisories/GHSA-fcm2-6c3h-pg6j
Credits
The containerd project would like to thank David Korczynski and Adam Korczynski of ADA Logics for responsibly disclosing this issue in accordance with the containerd security policy during a security audit sponsored by CNCF and facilitated by OSTIF.
For more information
If you have any questions or comments about this advisory:
Open an issue in containerd Email us at security@containerd.io
Impact
A bug was found in containerd where containers launched through containerd’s CRI implementation with a specially-crafted image configuration could gain access to read-only copies of arbitrary files and directories on the host. This may bypass any policy-based enforcement on container setup (including a Kubernetes Pod Security Policy) and expose potentially sensitive information. Kubernetes and crictl can both be configured to use containerd’s CRI implementation.
Patches
This bug has been fixed in containerd 1.6.1, 1.5.10 and 1.4.13. Users should update to these versions to resolve the issue.
Workarounds
Ensure that only trusted images are used.
Credits
The containerd project would like to thank Felix Wilhelm of Google Project Zero 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