QuoteA flaw in Windows Firewall may prevent users from seeing all the open network ports on a Windows XP or Windows Server 2003 computer.
The flaw manifests itself in the way the security application handles some entries in the Windows Registry, Microsoft said in a security advisory published Wednesday. The Windows Registry stores PC settings and is a core part of the operating system.
Full details and link to Microsoft briefing at:
CNET news report (http://news.com.com/Windows+Firewall+flaw+may+hide+open+ports/2100-7355_3-5845850.html?part=rss&tag=5845850&subj=news)