Description
In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can cause a denial of service by crafting a TCP exchange that triggers an exhaustion of the stack and a crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.10 version. A workaround is to restrict the maximum number of queries on incoming TCP connections to a safe value, like 50, via the setMaxTCPQueriesPerConnection setting. We would like to thank Renaud Allard for bringing this issue to our attention.
Problem types
CWE-674 Uncontrolled Recursion
Product status
1.9.10 (semver)
Credits
Renaud Allard
References
dnsdist.org/...es/powerdns-advisory-for-dnsdist-2025-03.html