CVE-2024-25581

Publication date 14 May 2024

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

When incoming DNS over HTTPS support is enabled using the nghttp2 provider, and queries are routed to a tcp-only or DNS over TLS backend, an attacker can trigger an assertion failure in DNSdist by sending a request for a zone transfer (AXFR or IXFR) over DNS over HTTPS, causing the process to stop and thus leading to a Denial of Service. DNS over HTTPS is not enabled by default, and backends are using plain DNS (Do53) by default.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
dnsdist	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected

Notes

sbeattie

introduced in dnsdist 1.9.0, earlier versions not affected.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
dnsdist	Upstream: https://downloads.powerdns.com/patches/2024-03/dnsdist-1.9.3-CVE-2024-25581.patch

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H