c-ares is an asynchronous resolver library. c-ares is vulnerable to denial of service. If a target resolver sends a query, the attacker forges a malformed UDP packet with a length of 0 and returns them to the target resolver. The target resolver erroneously interprets the 0 length as a graceful shutdown of the connection. This issue has been patched in version 1.19.1.
https://www.debian.org/security/2023/dsa-5419
https://security.netapp.com/advisory/ntap-20240605-0004/
https://security.gentoo.org/glsa/202310-09
https://lists.debian.org/debian-lts-announce/2023/06/msg00034.html
https://github.com/c-ares/c-ares/security/advisories/GHSA-9g78-jv2r-p7vc