Secunia released the following advisory (SA22876) today - marked as non-critical, it impacts exposure of sensitive information for VMware ESX Server 3.x.
Description:
A security issue has been reported in VMware ESX Server, which can be exploited by malicious, local users to disclose potentially sensitive information.
This patch is for ESX Server 3.0.0 only.
The instructions fxsave and fxrstor on AMD CPUs are used to save or restore the FPU registers (FOP, FIP and FDP). On AMD Opteron Processors, these instructions do not save/restore some exception related registers unless an exception is currently being serviced. This can lead to a security hole that allows local attackers to monitor the execution path of FPU processes, possibly allowing them to obtain sensitive information being passed through those processes.
Note: This vulnerability exists for all AMD Athlon, Duron, Athlon MP, Athlon XP, Athlon64, Athlon64 FX, Opteron, Turion, and Sempron processors but the AMD Opteron processors are the only AMD processors supported with ESX Server.
The Patch
The issue described above is fixed by ESX Server 3.0.0 Patch ESX-2533126. The issue has already been addressed in ESX Server 3.0.1.
This patch closes the security hole for AMD processors used with ESX 3.0.0, preventing attackers from monitoring the FPU execution path. This patch does not apply to ESX Server versions 3.0.1 and higher. The vulnerability has already been addressed in later versions of ESX Server. By default, the ESX Server host will reboot after the patch is applied.
Download Instructions
Download patch ESX-2533126 from http://www.vmware.com/download/vi/.
For more information, visit the following VMware KB or Secunia, here.