AuthoritativeApplication · Powerdns

CVE-2020-24697

HIGH · 7.5 CVSS v3.1 Published 2020-10-02
Fix available
A fix is available. Upgrade to after 4.3.0 or later.
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
An issue was discovered in PowerDNS Authoritative through 4.3.0 when --enable-experimental-gss-tsig is used. A remote, unauthenticated attacker can cause a denial of service by sending crafted queries with a GSS-TSIG signature.

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

PowerDNS Authoritative Server versions through 4.3.0 contain a denial-of-service vulnerability in the experimental GSS-TSIG feature. When this feature is enabled at compile time (--enable-experimental-gss-tsig), a remote unauthenticated attacker can trigger a crash or hang by sending specially crafted queries containing malformed GSS-TSIG signatures, causing the server to fail processing legitimate requests.

MitigationDisable the experimental GSS-TSIG feature if currently enabled, or upgrade to PowerDNS Authoritative Server 4.3.1 or later which contains the security fix. If GSS-TSIG is required for legitimate DNSSEC key management, apply the vendor patch immediately.

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
AuthoritativeApplication
Affected:<= 4.3.0

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
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Identify PowerDNS Authoritative Server version
    Run 'pdns --version' or 'pdns_server --version' to display the installed version number, or use the package manager (e.g., 'rpm -q pdns' or 'dpkg -l pdns')
    Affected if The reported version is 4.3.0 or lower, indicating the server is within the affected version range
  2. Confirm GSS-TSIG was compiled in
    Run 'pdns --config' or 'pdns_server --config' and search for any gss-tsig related options in the output. If GSS-TSIG was compiled with --enable-experimental-gss-tsig, related configuration directives will appear in the available settings
    Affected if GSS-TSIG options are present in the configuration output, meaning the feature was compiled into the binary
  3. Check for active GSS-TSIG configuration
    Inspect the PowerDNS configuration file (typically /etc/pdns/pdns.conf or /etc/powerdns/pdns.conf) for directives such as 'gss-tsig-enable', 'gss-tsig-keytab', or 'gss-tsig-algorithm'
    Affected if Any gss-tsig configuration directives are found with non-comment entries, meaning the feature is actively enabled
  4. Review runtime logs for GSS-TSIG activity
    Examine PowerDNS logs (journalctl -u pdns, syslog, or /var/log/pdns.log) for entries containing 'GSS' or 'TSIG' which indicate the feature has been used or attempted
    Affected if Logs show GSS-TSIG related queries or errors, confirming the feature is processing GSS-TSIG requests

The environment is affected only if PowerDNS Authoritative Server version is 4.3.0 or lower AND the GSS-TSIG feature was compiled in with --enable-experimental-gss-tsig AND is enabled in the configuration or actively processing GSS-TSIG queries.

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
Upgrade available Upgrade to a release after 4.3.0
Interim mitigation

Disable the experimental GSS-TSIG feature if currently enabled, or upgrade to PowerDNS Authoritative Server 4.3.1 or later which contains the security fix. If GSS-TSIG is required for legitimate DNSSEC key management, apply the vendor patch immediately.

Fix this in Authoritative Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,380
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Scan for this in your stack

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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-2020-24697 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