Microsoft Windows is prone to a local privilege-escalation vulnerability that occurs in the Windows kernel. An attacker can exploit this issue to execute arbitrary code with kernel-level privileges. Successful exploits will result in the complete compromise of affected computers.
Permit local access for trusted individuals only. Where possible, use restricted environments and restricted shells.
To reduce the likelihood of attacks, allow access to trusted individuals only and implement restricted environments and privileges.
Implement multiple redundant layers of security.
Various memory-protection schemes (such as nonexecutable and randomly mapped memory segments) may hinder an attacker's ability to exploit this vulnerability to execute arbitrary code.
Microsoft has released a security bulletin and updates. Please see the references for details.