After Stuxnet hit, it was discovered that it took advantage of four previously unknown Windows zero-day vulnerabilities to spread and compromise targeted systems.

Three of those have already been patched by Microsoft - the LNK vulnerability, the vulnerability located in the Print Spooler service, and a Windows XP local privilege escalation flaw - but the fourth one still remains unpatched.

That wouldn't be such a major problem, if it weren't for the fact that someone whose Internet handle is webDEViL hadn't released Proof-of-Concept exploit code for it.

While we could all use an out-of-band patch to plug the hole, it is doubtful that Microsoft will provide one since the flaw can be abused only if the attacker has already managed to access a limited account on the compromised system.