PowerDNS Security Advisory 2025-02 for DNSdist: Denial of service via crafted DoH exchangeΒΆ

  • 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
  • Exploit: This problem can be triggered by an attacker crafting a DoH exchange
  • Risk of system compromise: None
  • Solution: Upgrade to patched version or temporarily switch to the h2o provider
  • 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

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, only for configurations where incoming DoH is enabled via the nghttp2 provider.

The remedy is: upgrade to the patched 1.9.9 version.

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.