CVE-2021-43979

Name: CVE-2021-43979
Creator: NVD / NIST
Published: 2021-11-17T19:15:09.22+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.02%

Last modified Jun 17, 2026

CVE-2021-43979 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Styra Open Policy Agent (OPA) Gatekeeper through 3.7.0 mishandles concurrency, sometimes resulting in incorrect access control. The data replication mechanism allows policies to access the Kubernetes cluster state. EPSS estimates a 1.02% chance of exploitation in the next 30 days.

Description

Styra Open Policy Agent (OPA) Gatekeeper through 3.7.0 mishandles concurrency, sometimes resulting in incorrect access control. The data replication mechanism allows policies to access the Kubernetes cluster state. During data replication, OPA/Gatekeeper does not wait for the replication to finish before processing a request, which might cause inconsistencies between the replicated resources in OPA/Gatekeeper and the resources actually present in the cluster. Inconsistency can later be reflected in a policy bypass. NOTE: the vendor disagrees that this is a vulnerability, because Kubernetes states are only eventually consistent

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

1.02%

58.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-670

Affected Software

Vendor	Product	Versions
Openpolicyagent	Gatekeeper	<= 3.7.0

References

https://github.com/hkerma/opa-gatekeeper-concurrency-issueThird Party Advisory
https://github.com/open-policy-agent/gatekeeper/releasesPatch, Third Party Advisory
https://github.com/hkerma/opa-gatekeeper-concurrency-issueThird Party Advisory
https://github.com/open-policy-agent/gatekeeper/releasesPatch, Third Party Advisory

Timeline

Published: Nov 17, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43979?

How severe is CVE-2021-43979?

CVE-2021-43979 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.02% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43979?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43979?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST