The ValidateUserLogon function in provider/libserver/ECSession.cpp in Zarafa 7.1.8, 6.20.0, and earlier, when using certain build conditions, allows remote attackers to cause a denial of service (crash) via vectors related to "a NULL pointer of the password."
https://bugzilla.redhat.com/show_bug.cgi?id=1059903
http://www.mandriva.com/security/advisories?name=MDVSA-2014:044