Description: Multiple vulnerabilities have been identified in Internet Explorer, which in combination can be exploited to compromise a user's system.
1) A redirection feature using the "mhtml:" URI handler can be exploited to bypass a security check in Internet Explorer, which normally blocks web pages in the "Internet" zone from parsing local files.
2) The above redirection feature can also be exploited to download and execute a malicious file on a user's system. Successful exploitation requires that script code can be executed in the "MyComputer" zone.
3) A cross-site scripting vulnerability can be exploited to execute script code in the security zone associated with another web page if it contains a subframe. This may potentially allow execution of script code in the "MyComputer" zone.
4) A variant of a fixed vulnerability can still be exploited to hijack a user's clicks and perform certain actions without the user's knowledge.
5) An error in the download functionality can be exploited to disclose a user's cache directory by supplying a "HTM" file extension and an invalid value in the "Content-Type:" header field. This issue does not affect all versions and may have been fixed by the latest patch for Internet Explorer.
The vulnerabilities have been reported in Internet Explorer 6.0. However, other versions may also be affected and have been added due to the criticality of these issues.
PoC exploits (Proof of Concept) are available.
Do you have this product installed on your home computer? Scan using the free Personal Software Inspector. Check if a vulnerable version is installed on computers in your corporate network, using the Network Software Inspector.
Solution: Apply patches manually or via WindowsUpdate.
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