[oss-security] PowerDNS Security Advisory 2025-02: Denial of service via crafted DoH exchange

[Remi Gacogne]

Hi all,








The full security advisory is provided below, and can also be
found at
https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2025-02.html

A minimal patch can also be found here:
https://downloads.powerdns.com/patches/2025-02/

Please feel free to contact me directly if you have any question.



- CVE: CVE-2025-30194
- Date: 2025-04-29T12:00:00+02:00
- Discovery date: 2025-04-25T21:55:00+02:00
- Affects: PowerDNS DNSdist from 1.9.0 up to 1.9.8
- Not affected: PowerDNS DNSdist 1.9.9 and versions before 1.9.0
- Severity: High
- Impact: Denial of service

- Risk of system compromise: None

- CWE: CWE-416
- CVSS: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Last affected: 1.9.8
- First fixed: 1.9.9
- Internal ID: 297





The remedy is: upgrade to the patched 1.9.9 version.






Best regards,
--
Remi Gacogne
PowerDNS.COM BV - https://www.powerdns.com/

We released PowerDNS DNSdist 1.9.9 today, an emergency release fixing a security issue tracked as CVE-2025-30194 where a remote, unauthenticated attacker can cause a denial of service via a crafted DNS over HTTPS connection. The issue was reported to us via our public GitHub tracker, so once it was clear that the issue had a security impact we prepared to release a new version as soon as possible. While we advise upgrading to a fixed version, a work-around is to temporarily switch to the h2o provider until DNSdist has been upgraded. We would like to thank Charles Howes for bringing this issue to our attention. PowerDNS Security Advisory 2025-02 for DNSdist: Denial of service via crafted DoH exchange - Exploit: This problem can be triggered by an attacker crafting a DoH exchange - Solution: Upgrade to patched version or temporarily switch to the h2o provider When DNSdist is configured to provide DoH via the nghttp2 provider, an attacker can cause a denial of service by crafting a DoH exchange that triggers an illegal memory access (double-free) and crash of DNSdist, causing a denial of service. CVSS Score: 7.5 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, only for configurations where incoming DoH is enabled via the nghttp2 provider. A workaround is to temporarily switch to the h2o provider until DNSdist has been upgraded to a fixed version. We would like to thank Charles Howes for bringing this issue to our attention.

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