CVE-2024-25583Network attack vector

Service interruption via cyclic CNAME chain processing

Published Apr 25, 2024 · Updated Feb 13, 2025

Denial of service in PowerDNS Recursor 4.8.7, 4.9.4, and 5.0.3 allows remote attackers to interrupt DNS resolution. SyncRes::updateCacheFromRecords follows CNAME targets while building a wildcard-candidate chain but failed to stop when a target name was already present, so a cyclic CNAME response caused unbounded processing. An attacker must publish a crafted zone reached through a configured recursive forwarder; the default configuration is unaffected, and no compromise beyond service interruption is reported.

CVSS severity7.5
High
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in PowerDNS Recursor 4.8.7, 4.9.4, and 5.0.3 allows remote attackers to interrupt DNS resolution. SyncRes::updateCacheFromRecords follows CNAME targets while building a wildcard-candidate chain but failed to stop when a target name was already present, so a cyclic CNAME response caused unbounded processing. An attacker must publish a crafted zone reached through a configured recursive forwarder; the default configuration is unaffected, and no compromise beyond service interruption is reported.

The record

CVE
CVE-2024-25583
Published
Apr 25, 2024
Updated
Feb 13, 2025
Vendor
PowerDNS
Product
PowerDNS Authoritative Server
Classifications
CWE-20, CAPEC-25, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 25, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.8.7
  2. Affected versionversion=4.9.4
  3. Affected versionversion=5.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PowerDNS · PowerDNS Authoritative Serverversion=4.8.7; version=4.9.4; version=5.0.3
PowerDNS · PowerDNS Recursorversion=4.8.7; version=4.9.4; version=5.0.3

Published CVSS scores

7.5PowerDNSCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CAPEC-25Forced Deadlock
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo