GHSA-36xw-fx78-c5r4 is a medium-severity (CVSS 5.2) CWE-669 vulnerability in github.com/containerd/containerd. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-36xw-fx78-c5r4 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
containerd-shim API Exposed to Host Network Containers
Real-World Exposure
github.com/containerd/containerd🐹github.com/containerd/containerdReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Access controls for the shim’s API socket verified that the connecting process had an effective UID of 0, but did not otherwise restrict access to the abstract Unix domain socket. This would allow malicious containers running in the same network namespace as the shim, with an effective UID of 0 but otherwise reduced privileges, to cause new processes to be run with elevated privileges.
Specific Go Packages Affected
github.com/containerd/containerd/cmd
Patches
This vulnerability has been fixed in containerd 1.3.9 and 1.4.3. Users should update to these versions as soon as they are released. It should be noted that containers started with an old version of containerd-shim should be stopped and restarted, as running containers will continue to be vulnerable even after an upgrade.
Workarounds
If you are not providing the ability for untrusted users to start containers in the same network namespace as the shim (typically the "host" network namespace, for example with docker run --net=host or hostNetwork: true in a Kubernetes pod) and run with an effective UID of 0, you are not vulnerable to this issue.
If you are running containers with a vulnerable configuration, you can deny access to all abstract sockets with AppArmor by adding a line similar to deny unix addr=@**, to your policy.
It is best practice to run containers with a reduced set of privileges, with a non-zero UID, and with isolated namespaces. The containerd maintainers strongly advise against sharing namespaces with the host. Reducing the set of isolation mechanisms used for a container necessarily increases that container's privilege, regardless of what container runtime is used for running that container.
Credits
The containerd maintainers would like to thank Jeff Dileo of NCC Group for responsibly disclosing this issue in accordance with the containerd security policy and for reviewing the patch.
For more information
If you have any questions or comments about this advisory:
- Open an issue
- Email us at [email protected] if you think you’ve found a security bug.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/containerd/containerd | all versions | 1.3.9 |
| 🐹Go | github.com/containerd/containerd | ≥ 1.4.0&&< 1.4.3 | 1.4.3 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containerd/containerd. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/containerd/containerd to 1.3.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-36xw-fx78-c5r4 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-36xw-fx78-c5r4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-36xw-fx78-c5r4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
* The container runtime in OpenShift Container Platform 4 is cri-o which is not affected by this flaw. It doesn't make use of abstract unix sockets like containerd, which lead to this vulnerability being possible. * Red Hat Advanced Cluster Management for Kubernetes is not affected by this flaw. While containerd is…
Frequently Asked Questions
Is GHSA-36xw-fx78-c5r4 in your dependencies?
O3 detects GHSA-36xw-fx78-c5r4 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.