PGP Desktop before 9.10 allows local users to (1) cause a denial of service (crash) via a crafted IOCTL request to pgpdisk.sys, and (2) cause a denial of service (crash) and execute arbitrary code via a crafted IRP in an IOCTL request to pgpwded.sys.
The PGPwded device driver (aka PGPwded.sys) in PGP Corporation PGP Desktop 9.0.6 build 6060 and 9.9.0 build 397 allows local users to cause a denial of service (system crash) and possibly gain privileges via a certain METHOD_BUFFERED IOCTL request that overwrites portions of memory, related to a "Driver Collapse." NOTE: some of these details are obtained from third party information.