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

Published: 2021-11-17 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-43979 is rated Moderate Risk (41.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.91%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-43979

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.22% 0.91% +0.69%
2 2025-03-17 0.05% 0.22% +0.17%
3 2023-03-07 — 0.05% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-43979

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-43979

Affected software / configurations for CVE-2021-43979

Vendor Product Version Raw CPE
openpolicyagent gatekeeper <= 3.7.0 cpe:2.3:a:openpolicyagent:gatekeeper:*:*:*:*:*:*:*:*

References for CVE-2021-43979

cvelogic Threat Intelligence