An issue was discovered in InspIRCd 2 before 2.0.29 and 3 before 3.6.0. The pgsql module contains a use after free vulnerability. When combined with the sqlauth or sqloper modules, this vulnerability can be used for remote crashing of an InspIRCd server by any user able to connect to a server.
https://www.debian.org/security/2020/dsa-4764
https://lists.debian.org/debian-lts-announce/2020/09/msg00015.html
https://github.com/inspircd/inspircd/compare/v2.0.28...07d7dea
https://github.com/inspircd/inspircd/compare/426d1c8...b3f1db9