ircu < 2.10.12.12 and snircd < 1.3.4 - Denial of Service via Malformed MODE Command
The send_user_mode function in s_user.c in (1) Undernet ircu 2.10.12.12 and earlier, (2) snircd 1.3.4 and earlier, and unspecified other ircu derivatives allows remote attackers to cause a denial of service (daemon crash) via a malformed MODE command.