# CVE-2021-21334: containerd: In containerd (an industry-standard container runtime) before versions 1.3.10 and 1.4.4, containers launched through...

CVE-2021-21334 is fixed in 3 products on 1 platform, first by containerd 1.3.3-0ubuntu2.3, released March 4, 2021. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-21334
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0203
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 4, 2021

## Description

In containerd (an industry-standard container runtime) before versions 1.3.10 and 1.4.4, containers launched through containerd's CRI implementation (through Kubernetes, crictl, or any other pod/container client that uses the containerd CRI service) that share the same image may receive incorrect environment variables, including values that are defined for other containers. If the affected containers have different security contexts, this may allow sensitive information to be unintentionally shared. If you are not using containerd's CRI implementation (through one of the mechanisms described above), you are not vulnerable to this issue. If you are not launching multiple containers or Kubernetes pods from the same image which have different environment variables, you are not vulnerable to this issue. If you are not launching multiple containers or Kubernetes pods from the same image in rapid succession, you have reduced likelihood of being vulnerable to this issue This vulnerability has been fixed in containerd 1.3.10 and containerd 1.4.4. Users should update to these versions.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | containerd Ubuntu 18.04.6 LTS (bionic) | 1.5.2-0ubuntu1~18.04.2 | [containerd 1.5.2-0ubuntu1~18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-containerd-1.5.2-0ubuntu1-18.04.2.md) | Jul 19, 2021 |
| Linux | containerd Ubuntu 20.04 LTS (focal) | 1.3.3-0ubuntu2.3 | [containerd 1.3.3-0ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-containerd-1.3.3-0ubuntu2.3.md) | Mar 4, 2021 |
| Linux | golang-github-containerd-containerd-dev Ubuntu 18.04.6 LTS (bionic) | 1.5.2-0ubuntu1~18.04.2 | [golang-github-containerd-containerd-dev 1.5.2-0ubuntu1~18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-golang-github-containerd-containerd-dev-1.5.2-0ubuntu1-18.04.2.md) | Jul 19, 2021 |
| Linux | golang-github-docker-containerd-dev Ubuntu 18.04.6 LTS (bionic) | 1.5.2-0ubuntu1~18.04.2 | [golang-github-docker-containerd-dev 1.5.2-0ubuntu1~18.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-golang-github-docker-containerd-dev-1.5.2-0ubuntu1-18.04.2.md) | Jul 19, 2021 |
| Linux | golang-github-docker-containerd-dev Ubuntu 20.04 LTS (focal) | 1.3.3-0ubuntu2.3 | [golang-github-docker-containerd-dev 1.3.3-0ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-golang-github-docker-containerd-dev-1.3.3-0ubuntu2.3.md) | Mar 4, 2021 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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