Microsoft has reported an issue in Virtual PC for Mac that may permit a local attacker to gain elevated privileges on a system hosting the software. This is due to insecure handling of temporary files by the setuid root VirtualPC_Services binary, potentially permitting a malicious local user to create a malicious symbolic link in place of the temporary file, which would result in corruption of files or a malicious local user gaining root privileges on the system.
Permit local access for trusted individuals only. Where possible, use restricted environments and restricted shells.
This issue could be exploited by a malicious local user. Do not permit untrusted individuals to have local access to systems. Where possible, place local users in restricted environments and shells to limit what actions they may perform.
Microsoft has released MS04-005, which includes updates to address this issue.