CVE-2021-43979Public exploitNetwork attack vector

Policy bypass via stale replicated cluster state

Published Nov 17, 2021 · Updated Aug 4, 2024

Concurrency flaw in Styra Open Policy Agent Gatekeeper 3.7.0 and earlier allows remote attackers to bypass Kubernetes admission policies. Its data-replication path evaluates admission requests before replicated cluster resources are synchronized, so concurrent creations can be checked against stale state. Reachability requires policies that consult replicated cluster data and concurrent Kubernetes resource requests; the vendor disputes the issue because cluster state is eventually consistent.

CVSS severity5.3
Medium
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Concurrency flaw in Styra Open Policy Agent Gatekeeper 3.7.0 and earlier allows remote attackers to bypass Kubernetes admission policies. Its data-replication path evaluates admission requests before replicated cluster resources are synchronized, so concurrent creations can be checked against stale state. Reachability requires policies that consult replicated cluster data and concurrent Kubernetes resource requests; the vendor disputes the issue because cluster state is eventually consistent.

The record

CVE
CVE-2021-43979
Published
Nov 17, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-670
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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