Dynamoo writes "Microsoft released yesterday a whole bunch of critical security updates. Out of these, MS03-043 is a flaw in the Windows Messenger Service (not MSN Messenger) with the possibility of a remote attacker gaining complete control of a Windows NT/2000/XP/2003 based PC remotely. If this sounds like another possible vector for a worm to spread, you'd probably be right. Microsoft's recommendation is to 'disable the Messenger Service immediately and evaluate their need to deploy the patch'. Of course a firewall will offer some protection but shouldn't be relied on. At least administrators can disable the Messenger Service remotely. Of course this is another headache for admins still patching for last month's RPC flaw."