Microsoft delivered six patches on Tuesday - four critical - as part of its regular Patch Tuesday update cycle.

High on the critical list are patches for Outlook Express and Windows Mail, which cover flaws in the handling of malformed NNTP (Network News Transfer Protocol) responses, and a cumulative update for Internet Explorer 7.

Critical vulnerabilities in Word and Kodak Image Viewer also lend themselves to remote code execution.

All these risks are pretty severe, but some are more severe than others. The Word vulnerability has been abused in targeted exploits, the SANS Institute's Internet Storm Centre reports, and therefore ought to be a higher priority for patching.

Redmond also released two patches that earned the less severe "important" rating. These updates cover a privilege elevation bug in Sharepoint portal software and a denial of service bug in Windows RPC.

Microsoft's summary of the patches can be found here. A useful overview from the SANS Institute's Internet Storm Centre, which gives a better idea of patching priorities, can be found here. ®

Related stories

MS Explorer foundering after UFO strike (23 November 2007)
Databases still open to basic attack (15 November 2007)
Windows update offers defence against shell bug (14 November 2007)
Exploit Wednesday follows Patch Tuesday Word update (11 October 2007)
Coming to a Windows PC near you: 4 critical security updates (5 October 2007)
Doomwatchers sound Windows and IE vuln alarm (19 September 2007)
Patch Tuesday update triggered Skype outage (20 August 2007)
ISP panicked by MS Patch Tuesday (16 August 2007)
Oracle drops litter of summer patches (18 July 2007)
MS update sends PCs 'haywire' (12 July 2007)