CVE 2008-4915
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.
See the 
CVE page on Mitre.org
for more details.
