Unreal ircd versions below 3.2 suffer from a faulty cloaking scheme to hide IP addresses which allows attackers to find the true IP address of people using the server.
d901f38d951f9aa8638cbfc94e41963657c89bd9fb4970a2f94b7697d076e1e4
Unreal Decloak Toolkit version 0.1 illustrates the weak hashing system vulnerability in Unreal ircd 3.2 and previous versions.
b9f87a775c864e80c21ef6545cc72dbd0c4a0132cffc171c5d13262d8058894b