Critical IE, Vista Flaws Patched

Internet Explorer is suffering from six vulnerabilities, five privately reported and one publicly disclosed, all of which are addressed in security bulletin MS07-033. Microsoft officials said June 12 that all but one of the IE flaws could allow system hijacking if a user were to visit a malicious Web page. One of the flaws allows spoofing and also requires a malicious Web page visit.

In all cases of possible remote code execution, users who have configured IE to have fewer user rights could be at less risk than those running IE with administrative rights. For one of the vulnerabilities—the spoofing problem—user interaction is required.

Microsoft officials said the IE problem is critical for Windows XP SP2, Professional x64 Edition and x64 Edition SP2. The vulnerabilities also affect other versions to a degree that Microsoft deems either important or moderate; details and the update addressing the problems can be found under the Affected Software and Download Locations section of Microsoft's Security Bulletin Summary page.

IE is also involved in Microsoft's Security Bulletin MS07-034, another critical advisory that covers four vulnerabilities in Windows Mail in Windows Vista. Three of the flaws could let information slip out if users visit malicious pages using IE—this particular flaw can't be exploited directly in Outlook Express. The fourth vulnerability allows for remote system hijacking if a user views malicious e-mail with Windows Mail in Windows Vista.

Again, users who've configured their accounts with fewer rights are less at risk than those running with administrative rights. For a list of affected software, criticality on particular versions and download locations for fixes, go to Microsoft's Security Bulletin Summary page and look under the Affected Software and Download Locations section.
The third critical security advisory has to do with the Schannel Security Package in Windows. This package implements the SSL (Secure Sockets Layer) and TLS (Transport Layer Security) authentication protocols. The vulnerability could lead to remote code execution if a user visits a malicious page using a browser or an application that uses SSL/TLS.

But even though Microsoft dubbed the flaw critical, the Redmond, Wash., company also says attempts to exploit the vulnerability probably would only wind up with the browser or application exiting. "The system would not be able to connect to Web sites or resources using SSL or TLS until a restart of the system," according to Security Bulletin MS07-031.

This flaw affects Windows, Outlook Express and Windows Mail. Again, see Microsoft's advisory site for more version details and download locations.


The final critical advisory, Security Bulletin MS07-035, addresses a vulnerability in a Win32 API that could allow for system hijacking or privilege escalation when the API is used locally by a maliciously crafted application. Applications that use this Win32 API can be used as a vector to exploit the flaw. IE, for example, uses this Win32 API function when parsing specially crafted Web pages.

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