Out of the 13 updates, 5 are labeled as Critical, 7 are ranked as important, and one was labeled as moderate. Eleven of the 13 updates affects one or more editions of Windows, the remaining 2 updates affect Office XP and Office 2003 on Windows and Office 2004 for Mac.
Microsoft will also patch the 17-year-old bug in the kernel of all 32-bit versions of Windows. The vulnerability in the Windows VDM subsystem was publicly disclosed Jan. 19 by Google engineer Tavis Ormandy
The one update runs counter to the norm. It is rated as critical for Windows XP, Important for Vista, and Critical again for Windows 7. Because Vista and Windows 7 share a code base, vulnerabilities that affect them are almost always ranked identically.