CVE-2021-21334

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.

How to fix CVE-2021-21334

To remediate CVE-2021-21334, upgrade the affected package to a fixed version below.

• —upgrade to 1.4.4~ds1-1 or later
• —upgrade to 1.4.4 or later

Is CVE-2021-21334 being exploited?

Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 1.4.4~ds1-1
• >= 1.4.0, < 1.4.4

CVSS scores

References (14)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-21334
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-21334
• WEBgithub.com/containerd/containerd/commit/05f951a3781f4f2c1911b05e61c160e9c30eaa8e
• WEBgithub.com/containerd/containerd/commit/2d9c8aa4b3f4313982c5c999af57212a1c5d144b