The CPU hardware emulation in VMware Workstation 6.0.5 and earlier and 5.5.8 and earlier; Player 2.0.x through 2.0.5 and 1.0.x through 1.0.8; ACE 2.0.x through 2.0.5 and earlier, and 1.0.x through 1.0.7; Server 1.0.x through 1.0.7; ESX 2.5.4 through 3.5; and ESXi 3.5, when running 32-bit and 64-bit guest operating systems, does not properly handle the Trap flag, which allows authenticated guest OS users to gain privileges on the guest OS.