Users of MSN Messenger 6.0 and 6.1 would be well advised to download the patches in Microsoft's latest security bulletin. This month's vulnerabilities includes one that allows snoopers to access your hard drive when you visit the same chat room as them.

Security specialists Symantec describe the risk as 'medium level', warning that users who do not block anonymous callers are in particular danger. You do not have to be in conversation with the attacker, just in the same chat room. If anonymous callers are blocked then attackers have to be identified on your address list. Otherwise they can peruse your hard drive undetected, accessing any sensitive data you may have stored there.

Stephen Toulouse, security program manager for the Microsoft Security Response Centre, says notification of the patch will be sent out through MSN Messenger early next week. However, regular users should probably apply the patch as soon as possible. It can be found on the MSN Messenger homepage.