znc.cpp in ZNC before 0.092 allows remote authenticated users to cause a denial of service (crash) by requesting traffic statistics when there is an active unauthenticated connection, which triggers a NULL pointer dereference, as demonstrated using (1) a traffic link in the web administration pages or (2) the traffic command in the /znc shell.
http://znc.svn.sourceforge.net/viewvc/znc?revision=2026&view=revision
http://znc.svn.sourceforge.net/viewvc/znc/trunk/znc.cpp?r1=2025&r2=2026&pathrev=2026
http://www.vupen.com/english/advisories/2010/1775
http://www.securityfocus.com/bid/40982
http://www.debian.org/security/2010/dsa-2069
http://sourceforge.net/projects/znc/files/znc/0.092/znc-0.092-changelog.txt/view
http://secunia.com/advisories/40523
http://lists.fedoraproject.org/pipermail/package-announce/2010-June/043044.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-June/043043.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-June/043000.html