Some vulnerabilities have been reported in VMWare ESX Server, which can be exploited by malicious people to gain knowledge of sensitive information, bypass certain security restrictions, cause a DoS (Denial of Service), gain escalated privileges, or compromise a system.  These vulnerabilities affect both ESX Server 2.x and 3.x.

Impact: Security Bypass, Exposure of sensitive information, Privilege escalation, DoS, System access

Solution: Apply Patches

-- ESX 3.0.1 --
Apply patch ESX 3.0.1 Patch ESX-9986131.

-- ESX 3.0.0 --
Apply patch ESX 3.0.0 Patch ESX-3069097.

-- ESX 2.5.4 --
Apply ESX 2.5.4 Upgrade Patch 3 (Build# 36502)

-- ESX 2.5.3 --
Apply ESX 2.5.3 Upgrade Patch 6 (Build# 35703)

-- ESX 2.1.3 --
Apply ESX 2.1.3 Upgrade Patch 4 (Build# 35803)

-- ESX 2.0.2 --
Apply ESX 2.0.2 Upgrade Patch 4 (Build# 35801)

Original Advisory:
http://www.vmware.com/support/vi3/doc/esx-9986131-patch.html
http://www.vmware.com/support/vi3/doc/esx-3069097-patch.html
http://www.vmware.com/support/esx25/doc/esx-254-200612-patch.html
http://www.vmware.com/support/esx25/doc/esx-253-200612-patch.html
http://www.vmware.com/support/esx21/doc/esx-213-200612-patch.html
http://www.vmware.com/support/esx2/doc/esx-202-200612-patch.html