# GHSA-c9cp-9c75-9v8c: containerd started with non-empty inheritable Linux process capabilities > Unprivileged users inside containers can escalate privileges via inheritable capabilities due to a containerd bug, requiring an upgrade to secure the environment. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 14 May 2024 - **Also known as:** GO-2024-2846 ## What is GHSA-c9cp-9c75-9v8c? GHSA-c9cp-9c75-9v8c is a vulnerability in github.com/containerd/containerd, published on 14 May 2024. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description ### Impact A bug was found in containerd where containers were incorrectly started with non-empty inheritable Linux process capabilities, creating an atypical Linux environment and enabling programs with inheritable file capabilities to elevate those capabilities to the permitted set during `execve(2)`. Normally, when executable programs have specified permitted file capabilities, otherwise unprivileged users and processes can execute those programs and gain the specified file capabilities up to the bounding set. Due to this bug, containers which included executable programs with inheritable file capabilities allowed otherwise unprivileged users and processes to additionally gain these inheritable file capabilities up to the container's bounding set. Containers which use Linux users and groups to perform privilege separation inside the container are most directly impacted. This bug did not affect the container security sandbox as the inheritable set never contained more capabilities than were included in the container's bounding set. ### Patches This bug has been fixed in containerd 1.5.11 and 1.6.2. Users should update to these versions as soon as possible. Running containers should be stopped, deleted, and recreated for the inheritable capabilities to be reset. This fix changes containerd behavior such that containers are started with a more typical Linux environment. Refer to `capabilities(7)` for a description of how capabilities work. Note that permitted file capabilities continue to allow for privileges to be raised up to the container's bounding set and that processes may add capabilities to their own inheritable set up to the container's bounding set per the rules described in the manual page. In all cases the container's bounding set provides an upper bound on the capabilities that can be assumed and provides for the container security sandbox. ### Workarounds The entrypoint of a container can be modified to use a utility like `capsh(1)` to drop inheritable capabilities prior to the primary process starting. ### For more information If you have any questions or comments about this advisory: * [Open an issue](https://github.com/containerd/containerd/issues/new) * Email us at [security@containerd.io](mailto:security@containerd.io) if you think you’ve found a security bug ## Which versions are affected by GHSA-c9cp-9c75-9v8c? 5 open source packages ship an affected version, including github.com/containerd/containerd. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/containerd/containerd` | Go | All versions | 1.5.11, 1.6.2 | | `github.com/containerd/containerd` | Go | All versions | 1.5.11 | | `github.com/containerd/containerd` | Go | All versions | 1.5.11 | | `github.com/containerd/containerd` | Go | From 1.6.0 | 1.6.2 | | `github.com/containerd/containerd` | Go | From 1.6.0 | 1.6.2 | ## How do I fix GHSA-c9cp-9c75-9v8c? Upgrade github.com/containerd/containerd to a fixed version for your release line: 1.5.11 or 1.6.2. ## Is GHSA-c9cp-9c75-9v8c being exploited? There is no known exploitation of GHSA-c9cp-9c75-9v8c in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for GHSA-c9cp-9c75-9v8c and fix it if it is affected. What it is: GHSA-c9cp-9c75-9v8c is a vulnerability in github.com/containerd/containerd, published on 14 May 2024. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of GHSA-c9cp-9c75-9v8c in the wild and no public exploit code. Affected packages and fixed versions: - github.com/containerd/containerd (Go): affected all versions; fixed in 1.5.11, 1.6.2 - github.com/containerd/containerd (Go): affected all versions; fixed in 1.5.11 - github.com/containerd/containerd (Go): affected all versions; fixed in 1.5.11 - github.com/containerd/containerd (Go): affected from 1.6.0; fixed in 1.6.2 - github.com/containerd/containerd (Go): affected from 1.6.0; fixed in 1.6.2 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/GHSA-c9cp-9c75-9v8c/ (Markdown: https://insights.sbomify.com/GHSA-c9cp-9c75-9v8c/index.md) ``` ## Sources - OSV: https://osv.dev/vulnerability/GHSA-c9cp-9c75-9v8c --- From sbomify Insights: https://insights.sbomify.com/GHSA-c9cp-9c75-9v8c/ Summaries are generated and may contain mistakes; the official description above is the record.