Vulnerability in Openpolicyagent Gatekeeper

CVE-2021-43979

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

EPSS: 0.010 (59.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-43979?
CVE-2021-43979 is a medium-severity vulnerability in Openpolicyagent Gatekeeper, classified under Always-Incorrect Control Flow Implementation. CVSS score: 5.3/10. Published 2021-11-17.
How severe is CVE-2021-43979?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-43979 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.