ZNC 1.0 allows remote authenticated users to cause a denial of service (NULL pointer reference and crash) via a crafted request to the (1) editnetwork, (2) editchan, (3) addchan, or (4) delchan page in modules/webadmin.cpp.
http://www.openwall.com/lists/oss-security/2013/05/30/3
http://www.mandriva.com/security/advisories?name=MDVSA-2015:013
http://secunia.com/advisories/53450
http://lists.fedoraproject.org/pipermail/package-announce/2013-August/114172.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-August/114144.html