Check Point Zone Labs Check Point Integrity Client

vsdatant.sys in Zone Lab ZoneAlarm before 5.5.062.011, ZoneAlarm Wireless before 5.5.080.000, Check Point Integrity Client 4.x before 4.5.122.000 and 5.x before 5.1.556.166 do not properly verify that the ServerPortName argument to the NtConnectPort function is a valid memory address, which allows local users to cause a denial of service (system crash) when ZoneAlarm attempts to dereference an invalid pointer.