CVE-2025-30194: Use-After-Free (CVSS 7.5)

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-416 Use After Free

References

Other 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

Frequently Asked Questions

What is 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. 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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-30194? +

CVE-2025-30194 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2025-30194? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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