\Device\NdisTapi (NDISTAPI.sys) in Microsoft Windows XP SP2 and 2003 SP1 uses weak permissions, which allows local users to write to the de…

\Device\NdisTapi (NDISTAPI.sys) in Microsoft Windows XP SP2 and 2003 SP1 uses weak permissions, which allows local users to write to the device and cause a denial of service, as demonstrated by using an IRQL to acquire a spinlock on paged memory via the NdisTapiDispatch function.