dbcve.org
Enterprise LinuxOperating system · Redhat

CVE-2021-20325

CRITICAL · 9.8 CVSS v3.1 Published 2022-02-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
Missing fixes for CVE-2021-40438 and CVE-2021-26691 in the versions of httpd, as shipped in Red Hat Enterprise Linux 8.5.0, causes a security regression compared to the versions shipped in Red Hat Enterprise Linux 8.4. A user who installs or updates to Red Hat Enterprise Linux 8.5.0 would be vulnerable to the mentioned CVEs, even if they were properly fixed in Red Hat Enterprise Linux 8.4. CVE-2021-20325 was assigned to that Red Hat specific security regression and it does not affect the upstream versions of httpd.

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 · high confidence

This is a Red Hat-specific security regression in httpd shipped with RHEL 8.5.0 where fixes for CVE-2021-40438 and CVE-2021-26691 were missing, compared to the properly fixed versions in RHEL 8.4. The regression reintroduces vulnerabilities that were previously resolved, exposing systems to the same risks present in those earlier CVEs.

MitigationOrganizations running RHEL 8.5.0 should apply Red Hat's security updates to restore the missing fixes for CVE-2021-40438 and CVE-2021-26691, effectively addressing CVE-2021-20325 through standard patch management.

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
Enterprise LinuxOperating system
Affected:= 8.5.0

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
High
Integrity
High
Availability
High

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

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. Verify RHEL version is 8.5.0
    Run `cat /etc/redhat-release` or `hostnamectl` to confirm the installed Red Hat Enterprise Linux version
    Affected if The system reports version 8.5.0 specifically
  2. Confirm httpd is installed
    Run `rpm -q httpd` to check if the Apache HTTP Server package is present
    Affected if httpd package is installed on the system
  3. Check installed httpd version
    Run `rpm -q --info httpd` and look at the Version field, or run `httpd -v` if the service is accessible
    Affected if The httpd version is earlier than the fixed versions present in RHEL 8.4 (compare your version number against the 8.4 release)

A system is affected if it runs RHEL 8.5.0 with the httpd package installed, where the httpd version is older than the patched versions that were available in RHEL 8.4 for CVE-2021-40438 and CVE-2021-26691.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Organizations running RHEL 8.5.0 should apply Red Hat's security updates to restore the missing fixes for CVE-2021-40438 and CVE-2021-26691, effectively addressing CVE-2021-20325 through standard patch management.

Recommended fix High confidence

Red Hat Enterprise Linux 8.6 or later (or latest RHEL 8.x update stream)

  1. Update the system package cache: sudo dnf check-update
  2. Upgrade httpd and related packages to the latest available version: sudo dnf update httpd
  3. Verify the installed version includes fixes for CVE-2021-40438 and CVE-2021-26691: rpm -q --changelog httpd | grep -E 'CVE-2021-40438|CVE-2021-26691'
  4. Restart the httpd service to apply the updated binaries: sudo systemctl restart httpd
Caveat Standard httpd update - test web application compatibility in staging before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Enterprise Linux Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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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-2021-20325 in production — separate from our analysis above.

No notes yet

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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
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