Microsoft has released seven security bulletins to patch 11 vulnerabilities in Windows, Internet Explorer, Windows Media Player and other parts of the operating system. Two of the bugs are currently being exploited by attackers, Microsoft confirmed.
Of the seven updates, three are rated critical - the highest ranking Microsoft uses - while the other four are labeled important, the second-highest category in the company's four-step scoring system.
The three critical bulletins, which fix seven different flaws in DirectX, the Windows Media Format runtime used in Windows Media Player and Internet Explorer, should be patched at once, said security experts. "These are the worst kind of client-side vulnerabilities that one could wish for," said Andrew Storms, director of security operations at nCircle. "All three of them deal with rich multimedia content.
"Obviously, attackers have moved away from sending malware and toward drive-by attacks," Storms added.
Amol Sarwate, the manager of Qualys's vulnerability lab, echoed Storms in both his choice of patches to administer first and his reasoning. "The three bulletins marked critical [include vulnerabilities that] are of the type we've seen attackers use to target common desktop users, rather than trying to attack servers."
Sarwate got a bit more specific, however, in pinpointing the single-most dangerous bug patched Tuesday: MS07-069, the bulletin that addresses four vulnerabilities in IE6 and IE7, should be deployed first, he advised, because one of those flaws is already being exploited in the wild. "The DHTML zero-day is extremely important to patch," said Sarwate.
The three critical updates - MS07-064, MS07-068 and MS07-069 - plug holes in DirectX, Windows Media Format runtime and IE6 and IE7, respectively. Six of the seven vulnerabilities covered by those updates were pegged as critical for Windows Vista, which Microsoft has touted as it most secure ever.
MS07-064 quashes a pair of bugs in the DirectX handles several streaming video file formats; hackers could exploit the vulnerabilities by duping users into viewing rigged streaming media, said Microsoft.