dbcve.org
OpenshiftApplication · Redhat

CVE-2021-4047

HIGH · 7.5 CVSS v3.1 Published 2022-04-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The release of OpenShift 4.9.6 included four CVE fixes for the haproxy package, however the patch for CVE-2021-39242 was missing. This issue only affects Red Hat OpenShift 4.9.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

OpenShift 4.9.6 was released with four CVE fixes for the haproxy package, but the patch for CVE-2021-39242 was inadvertently omitted from the release. This means the haproxy vulnerability addressed by CVE-2021-39242 remains unpatched in OpenShift 4.9 deployments that upgraded to 4.9.6.

MitigationOrganizations running OpenShift 4.9.6 should monitor for subsequent patch releases that include the missing CVE-2021-39242 fix, or consult Red Hat for the specific patch to remediate the haproxy vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OpenshiftApplication
Affected:= 4.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check OpenShift version
    Run 'oc get clusterversion' or 'oc version' to retrieve the installed OpenShift version
    Affected if The version shows 4.9.6 specifically
  2. Identify haproxy usage
    Run 'oc get pods -A | grep -i haproxy' or check for haproxy-related pods in the cluster, particularly in router components
    Affected if haproxy pods or processes are running in the cluster
  3. Inspect haproxy package version
    For the haproxy pods identified, exec into the container and run 'haproxy -v' or check the RPM package version with 'rpm -qa | grep haproxy'
    Affected if The haproxy version matches the vulnerable version range for CVE-2021-39242 (the underlying vulnerability that should have been patched)
  4. Check router component
    Run 'oc get deployment -n openshift-ingress' to find the router deployments, then inspect the image to determine the haproxy version bundled
    Affected if The router is using an unpatched haproxy version from the 4.9.6 release

A user is affected if running OpenShift 4.9.6 with haproxy-based router or ingress components present in the cluster.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Organizations running OpenShift 4.9.6 should monitor for subsequent patch releases that include the missing CVE-2021-39242 fix, or consult Red Hat for the specific patch to remediate the haproxy vulnerability.

Fix this in Openshift Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-4047 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-4047 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data