Description
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. 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.
Problem types
Product status
1.9.0 (semver) before 1.9.9
Credits
Charles Howes
References
www.openwall.com/lists/oss-security/2025/04/29/1
www.vicarius.io/...025-30194-detection-dnsdist-vulnerability
www.vicarius.io/...2025-30194-mitigate-dnsdist-vulnerability
dnsdist.org/...es/powerdns-advisory-for-dnsdist-2025-02.html