Reuters.com Microsoft Says Latest Software Flaw 'Critical':
SEATTLE (Reuters) - Microsoft Corp. (MSFT.O: Quote, Profile, Research) upgraded a recent security warning to 'critical' after discovering new ways in which an attacker could run malicious software on a vulnerable computer, the world's largest software maker said on Wednesday.
The software flaw, which affects the two latest versions of Microsoft's Outlook e-mail, calendar and contacts program, were initially rated as 'important' in Microsoft's monthly security bulletin issued on Tuesday.
Redmond, Washington-based Microsoft said that it reissued its latest security bulletin with a 'critical' rating, which means that software should download and install a patch to correct the problem as quickly as possible.
'This change is based on information concerning a new attack scenario discovered after the bulletin's original release on March 9th,' Microsoft said in a statement."