CVE-2021-21334
If the affected containers have different security contexts, this may allow sensitive information to be unintentionally shared.
Does this matter?
Lower severity and a low EPSS score (1.95%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 1.95% probability · 80th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-668
- Affected
- linuxfoundation/containerd · fedoraproject/fedora
- Source
- security-advisories@github.com
EPSS 1.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/containerd/containerd/commit/05f951a3781f4f2c1911b05e61c160e9c30eaa8ePatch, Third Party Advisory
- https://github.com/containerd/containerd/releases/tag/v1.3.10Release Notes, Third Party Advisory
- https://github.com/containerd/containerd/releases/tag/v1.4.4Release Notes, Third Party Advisory
- https://github.com/containerd/containerd/security/advisories/GHSA-6g2q-w5j3-fwh4Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KUE2Z2ZUWBHRU36ZGBD2YSJCYB6ELPXE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QIBPKSX5IOWPM3ZPFB3JVLXWDHSZTTWT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VTXHA5JOWQRCCUZH7ZQBEYN6KZKJEYSD/
- https://security.gentoo.org/glsa/202105-33Third Party Advisory
- https://github.com/containerd/containerd/commit/05f951a3781f4f2c1911b05e61c160e9c30eaa8ePatch, Third Party Advisory
- https://github.com/containerd/containerd/releases/tag/v1.3.10Release Notes, Third Party Advisory
- https://github.com/containerd/containerd/releases/tag/v1.4.4Release Notes, Third Party Advisory
- https://github.com/containerd/containerd/security/advisories/GHSA-6g2q-w5j3-fwh4Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KUE2Z2ZUWBHRU36ZGBD2YSJCYB6ELPXE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QIBPKSX5IOWPM3ZPFB3JVLXWDHSZTTWT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VTXHA5JOWQRCCUZH7ZQBEYN6KZKJEYSD/
- https://security.gentoo.org/glsa/202105-33Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.