CVE-2025-30194
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.24% probability · 82th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Source
- security@open-xchange.com
References
- https://dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2025-02.html
- http://www.openwall.com/lists/oss-security/2025/04/29/1
- https://www.vicarius.io/vsociety/posts/cve-2025-30194-detection-dnsdist-vulnerability
- https://www.vicarius.io/vsociety/posts/cve-2025-30194-mitigate-dnsdist-vulnerability
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.