ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2021-36754

powerdns authoritative_server Improper Restriction of Operations within the Bounds of a Memory Buffer

Published Oct 20, 2025 · catalog updated Oct 20, 2025 · powerdns authoritative_server Improper Restriction

Patch now

CVE-2021-36754 is in the CISA known-exploited catalog. Confirm powerdns authoritative_server Improper Restriction against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (powerdns authoritative_server Improper Restriction).
  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
64.86%
Remediation
Remediation guidance
Affected products
vendor powerdns authoritative_server

PowerDNS Authoritative Server 4.5.0 before 4.5.1 allows anybody to crash the process by sending a specific query (QTYPE 65535) that causes an out-of-bounds exception.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor powerdns authoritative_serverversion unspecified

How to fix CVE-2021-36754

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-36754 is in the CISA known-exploited catalog. Confirm powerdns authoritative_server Improper Restriction against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS 64.86%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 20, 2025 · VulnCheck KEV

    Detected

    PowerDNS Authoritative Server 4.5.0 before 4.5.1 allows anybody to crash the process by sending a specific query (QTYPE 65535) that causes an out-of-bounds exception.

  2. Oct 20, 2025 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Sources

  • CVE.orgVulnerability recordCVE-2021-36754

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-36754

    30-day exploitation probability 64.9%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-2021-36754

    PowerDNS Authoritative Server 4.5.0 before 4.5.1 allows anybody to crash the process by sending a specific query (QTYPE 65535) that causes an out-of-bounds exception.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.