The \\Device\\SymEvent driver in Symantec Norton Personal Firewall 2006 9.1.0.33 and other versions of Norton Personal Firewall Internet Security AntiVirus SystemWorks Symantec Client Security SCS 1.x 2.x 3.0 and 3.1 Symantec AntiVirus Corporate Edition SAVCE 8.x 9.x 10.0 and 10.1 Symantec pcAnywhere 11.5 only and Symantec Host allows local users to cause a denial of service (system crash) via invalid data as demonstrated by calling DeviceIoControl to send the data.