In a nutshell, it's another avenue to take control of a system, install programs and do other things. MS08-010 : This update fixes multiple flaws in IE that allow for remote code executions. Microsoft said: "The security update addresses these vulnerabilities by modifying the way that Internet Explorer handles HTML and validates data, as well as by setting the kill bit for an ActiveX control." Stray thought: You could just kill ActiveX. MS08-012 : This update resolves a remote code execution flaw in Microsoft Office Publisher. Affects Microsoft Office Publisher 2000; supported releases of Microsoft Office Publisher 2002; and supported editions of Microsoft Office Publisher 2003 Service Pack 2. MS08-013 : Microsoft's update here covers a remote code execution vulnerability in Office 2000. It's an important update for Microsoft Office XP, Microsoft Office 2003 and Microsoft Office 2004 for Mac.