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OpendkimApplication

CVE-2022-48521

MEDIUM · 5.3 CVSS v3.1 Published 2023-07-11
Fix available
A fix is available. Upgrade to after 2.10.3 or later.
See remediation →
62/100
Remediation priority · Elevated
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
An issue was discovered in OpenDKIM through 2.10.3, and 2.11.x through 2.11.0-Beta2. It fails to keep track of ordinal numbers when removing fake Authentication-Results header fields, which allows a remote attacker to craft an e-mail message with a fake sender address such that programs that rely on Authentication-Results from OpenDKIM will treat the message as having a valid DKIM signature when in fact it has none.

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

OpenDKIM fails to properly track ordinal numbers when removing fake Authentication-Results header fields, causing the wrong header to potentially remain or be removed incorrectly. This allows crafted emails with forged sender addresses to be incorrectly validated as having legitimate DKIM signatures by downstream systems that rely on OpenDKIM's Authentication-Results output.

MitigationApply the vendor patch when available; until then, implement supplementary email authentication validation or use alternative DKIM verification mechanisms to cross-check results.

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
OpendkimApplication
Affected:<= 2.10.3= 2.11.0

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
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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. Verify OpenDKIM is installed
    Run 'opendkim -V' or check via package manager (dpkg -l | grep opendkim on Debian/Ubuntu, rpm -qa | grep opendkim on RHEL/CentOS)
    Affected if OpenDKIM is not installed or the command fails - not affected
  2. Determine installed OpenDKIM version
    Run 'opendkim -V' and locate the version number in the output (typically displayed as 'OpenDKIM version X.Y.Z')
    Affected if Version cannot be determined from output - cannot assess
  3. Compare version to affected ranges
    Check if the installed version is 2.10.3 or lower, or exactly 2.11.0 (compare against: 2.10.3, 2.10.2, 2.10.1, 2.10.0, 2.9.x, 2.8.x, and 2.11.0 specifically)
    Affected if Version is <= 2.10.3 OR version equals 2.11.0 - environment is affected

If OpenDKIM is present and the running version falls within <= 2.10.3 or exactly 2.11.0, the flaw in header ordinal tracking during Authentication-Results removal is present and could allow forged emails to be incorrectly validated.

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
Upgrade available Upgrade to a release after 2.10.3
Interim mitigation

Apply the vendor patch when available; until then, implement supplementary email authentication validation or use alternative DKIM verification mechanisms to cross-check results.

Recommended fix Moderate confidence

OpenDKIM 2.11.0 (stable) or later, or 2.10.4 if backported

  1. Check current OpenDKIM version using 'opendkim -V' or package manager
  2. Backup current OpenDKIM configuration files (typically in /etc/opendkim.conf or /etc/dkim-filter.conf)
  3. Update package repository if using a package manager
  4. Upgrade OpenDKIM to version 2.11.0 stable or later (or 2.10.4 if that patch was backported)
  5. Verify the new version is installed using 'opendkim -V'
  6. Test email signing and verification to ensure proper functionality
  7. Restart the OpenDKIM service (e.g., 'systemctl restart opendkim' or 'service opendkim restart')
Caveat Review release notes for any configuration or behavior changes between affected and fixed versions; test thoroughly in staging before production deployment

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

Fix this in Opendkim Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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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-2022-48521 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data