hybserv2 1.9.2-1.9.4 - Denial of Service via MemoServ Private Message
mystring.c in hybserv in IRCD-Hybrid (aka Hybrid2 IRC Services) 1.9.2 through 1.9.4 allows remote attackers to cause a denial of service (daemon crash) via a ":help \t" private message to the MemoServ service.