Risk: Medium
Microsoft released 13 security bulletins - nine "critical" - in February 2005, making it its biggest monthly patch yet. Twelve patches fix multiple components in Windows and Windows-based applications and one updates an October 2004 alert to protect Exchange 2000 users against possible attack.
The most serious vulnerabilities involve security bugs in Windows licensing logging service (MS05-010), Windows Server Message Block (MS05-011) and multiple flaws in Internet Explorer (MS05-014) that might be used by crackers to gain complete control over targeted systems. A flaw in the way Windows Media Player and MSN Messenger process PNG files (MS05-009) carries a similar critical risk as do a bug in an ActiveX control in Windows involved with DHTML Editing (MS05-013) and a vulnerable Hyperlink Object Library in Windows (MS05-015).
A bug in Windows OLE and COM middleware components affecting Exchange and Office could let hackers run hostile code on vulnerable systems (MS05-012). Last, but not least, on the critical list is a patch to fix flaws with Office XP (MS05-005).
Three of the 12 new fixes issued by Microsoft are deemed "important". These are: a flaw in ASP.Net that could allow an attacker to gain unauthorized access to parts of a web site, a bug in Windows Shell Component that could allow an attacker to cause the affected system to stop responding, and a vulnerability in Windows Shared Resource Connection component that opens the way to unauthorised snooping. Lastly, a "moderate" flaw in Microsoft Sharepoint could allow cross-site scripting attacks. An advisory from US CERT gives an overview of the patches.
Redmond also revised an October 2004 bulletin to mark the availability of a patch for Exchange 2000 Server. Although initially thought safe, a variation in a remote code execution vulnerability has been found to affect Exchange 2000, prompting the release of a fix (MS04-035).
Microsoft advises users to visit Windows Update and Office Update to receive the updates that apply to their systems. Virtually all Windows users, including those who are using Win XP SP2, are going to need to do some patching. MSN Messenger 6.1 and 6.2 users will be automatically notified to upgrade when they sign in for the service.