Impact A bug was found in containerd where the CRI plugin propagates labels from an image config (LABEL instruction in Dockerfile) to a container without validation. This may result in executing an arbitrary command on the host, via a plugin that consumes container labels for some operations.

Patches This bug has been fixed in the following containerd versions:

2.3.2 2.2.5 2.1.9 2.0.10 1.7.33

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 Anthropic Research, in collaboration with Claude, the GKE Security Team using Gemini, and Robert Prast (@robertprast) for independently discovering and 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 Email us at security@containerd.io

Impact

containerd's CRI implementation improperly trusts Container Device Interface (CDI) annotations found within untrusted checkpoint image metadata during container restoration. When restoring a container from a checkpoint, containerd preserves CDI-related annotations from the checkpoint archive rather than relying solely on the pod's create-time specification. This allows a user with pod creation permissions to bypass standard Kubernetes resource allocation and device plugin enforcement, injecting arbitrary CDI edits (such as device nodes and host mounts) into the restored container. Successful exploitation requires that the node has CDI enabled and contains a matching host CDI specification for the requested device; environments where CDI is disabled or lacking sensitive device specifications are not affected.

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. Recreating existing containers restored from untrusted checkpoints may be necessary to remove smuggled configuration.

Workarounds

Users can mitigate this issue by restricting the restoration of containers from untrusted checkpoint images. If Container Device Interface (CDI) capabilities are not utilized on the node, removing or temporarily relocating host CDI specifications from the default directories (/etc/cdi and /var/run/cdi) will eliminate the reachability of this vulnerability.

Credits

The containerd project would like to thank Robert Prast (@robertprast) 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 Email us at security@containerd.io

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.

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 where containers launched with a numeric User directive that cannot be parsed as a 32-bit integer are incorrectly treated as a username. If a crafted image provides an /etc/passwd file mapping this large numeric string to root, the container ultimately runs as root (UID 0). This allows the Kubernetes runAsNonRoot restriction to be bypassed, causing unexpected behavior for environments that require containers to run as a non-root user.

Patches This bug has been fixed in the following containerd versions:

2.3.1 2.2.4 2.0.9 1.7.32

Note: The containerd 2.1 release has reached its end of life and a fixed version is not provided.

Users should update to these versions to resolve the issue.

Workarounds Ensure that only trusted images are used and that only trusted users have permissions to import images. Alternatively, enforcing a specific numeric runAsUser in the Kubernetes Pod securityContext overrides the USER directive in the image and prevents the bypass. Newer versions of Kubernetes, starting with 1.34, also appear to enforce runAsNonRoot properly regardless of this bug.

Credits The containerd project would like to thank Lei Wang (@ssst0n3) for responsibly disclosing this issue in accordance with the containerd security policy.

Resources https://github.com/advisories/GHSA-265r-hfxg-fhmg (CVE-2024-40635)

For more information

If there are any questions or comments about this advisory:

Open an issue in containerd Send an email to security@containerd.io

To report a security issue in containerd: Report a new vulnerability Send an email to security@containerd.io

Impact containerd's CRI checkpoint import process contains a vulnerability where it fails to validate the image references specified within a checkpoint image's configuration. An attacker with permissions to create pods can use a crafted checkpoint image to force containerd to pull a malicious image and assign it an arbitrary local tag, thereby poisoning the node's local image cache. Subsequently, if other pods on the same node attempt to use the poisoned tag with an IfNotPresent (or Never) pull policy, they will unknowingly execute the attacker's malicious image instead of the legitimate one. This can lead to a compromise of the affected pods, allowing the attacker to execute arbitrary code under the victim pod's identity.

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 Users should only allow trusted images to be pulled.

Credits The containerd project would like to thank Henry Beberman (@hbeberman) of Microsoft, the GKE Security Team using Gemini, Anthropic Research, in collaboration with Claude, and Robert Prast (@robertprast) who independently discovered and responsibly disclosed 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 Email us at security@containerd.io

Impact A vulnerability in containerd allows a maliciously crafted image to cause a Denial of Service (DoS) condition. When creating a container from this image, memory exhaustion occurs, leading to an Out Of Memory (OOM) kill of the containerd process. This renders the container runtime API unavailable and can disrupt clients such as the Docker Engine or Kubernetes control-plane components.

Patches This bug has been fixed in the following containerd versions:

2.3.2 2.2.5 2.1.9 2.0.10 1.7.33

Users should update to these versions to resolve the issue.

Workarounds Ensure that only trusted images are used and that only trusted users have permissions to import images or schedule pods.

Credits

The containerd project would like to thank Jakub Ciolek (@jake-ciolek) at AlphaSense and Kyle Elliott @ Trail of Bits who independently discovered and responsibly disclosed 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 Email us at security@containerd.io