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Public proof of conceptFix available

CVE-2021-36754

A public proof of concept exists; no exploitation attested.

  • Published2021-07-30
  • Fixed in4.5.1
  • WeaknessCWE-119

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2021-07-3014:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-36754?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-36754?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Powerdns authoritative server
BranchAffectedFixed in
4.5≥ 4.5.0, < 4.5.14.5.1

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • pdnsopenSUSE:Tumbleweedall versions · fixed in 4.5.1-1.5
  • pdnsCleanStartall versions · fixed in 4.5.1-r0
  • pdnsAlpine:v3.24all versions · fixed in 4.5.1-r0
  • pdnsAlpine:v3.23all versions · fixed in 4.5.1-r0
  • pdnsAlpine:v3.22all versions · fixed in 4.5.1-r0
  • pdnsAlpine:v3.21all versions · fixed in 4.5.1-r0
  • pdnsAlpine:v3.20all versions · fixed in 4.5.1-r0
  • pdnsAlpine:v3.19all versions · fixed in 4.5.1-r0

4 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-36754 Red Hat Product Security

    pdns: specific query crashes Authoritative Server

Full record on NVD

Fix

  1. Update Powerdns authoritative server to 4.5.1

Advisories and patches

Detection

read 2026-11-02 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • NVDweakness (CWE)CWE-119read 2026-10-23
  • FIRST EPSSEPSS score64.9 %read 2026-11-02
  • ProjectDiscoverydetectionread 2026-11-02
  • OSVaffected packages—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2021-07-30
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-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.

Is CVE-2021-36754 actively exploited?

Active exploitation of CVE-2021-36754 has not been confirmed. Its EPSS score was 64.9% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-36754?

CVE-2021-36754 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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Sources for this record