Multiple vulnerabilities have been reported in Microsoft Internet Explorer, which can be exploited by malicious people to compromise a user's system.

1) A use-after-free error when handling the Scroll event can be exploited to dereference an already freed object.

2) An error within OLEAuto32.dll when accessing an uninitialised object can be exploited to corrupt memory.

3) A use-after-free error when handling the Option element can be exploited to dereference an already freed object.

NOTE: This vulnerability does not affect Internet Explorer 9.

4) A use-after-free error when handling the OnLoad event can be exploited to dereference an already freed object.

NOTE: This vulnerability only affects Internet Explorer 6.

5) An error within Jscript9.dll when accessing an uninitialised object can be exploited to corrupt memory.

NOTE: This vulnerability only affects Internet Explorer 9.

6) An array-indexing error when handling the "add()" method of Select elements can be exploited to corrupt memory.

NOTE: This vulnerability only affects Internet Explorer 8.

7) A use-after-free error when handling the "swapNode()" method on a node within a document with two body nodes can be exploited to dereference an already freed object.

8) A logic error in the "SetExpandedClipRect()" function when handling an "extra size index" set to zero in certain CDispNode objects can be exploited to corrupt the virtual function table.

Successful exploitation of the vulnerabilities allows execution of arbitrary code.

Solution
Apply patches.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) The vendor credits Vishwas Sharma, McAfee Labs.
2, 5) The vendor credits David Bloom, Greplin.
3, 6) Ivan Fratric via ZDI.
4) GWSlabs via iDefense.
7) Sebastian Apelt via ZDI.
8) An anonymous person via ZDI.

Changelog
Further details available to Secunia VIM customers

Original Advisory
MS11-081 (KB2586448):
http://technet.microsoft.com/en-us/security/bulletin/ms11-081

iDefense:
http://www.verisigninc.com/en_US/products-and-services/network-intelligence-availability/idefense/public-vulnerability-reports/articles/index.xhtml?loc=en_US&id=948

Ivan Fratric:
http://ifsec.blogspot.com/2011/10/internet-explorer-option-element-remote.html
http://ifsec.blogspot.com/2011/10/internet-explorer-select-element-remote.html

ZDI:
http://www.zerodayinitiative.com/advisories/ZDI-11-287/
http://www.zerodayinitiative.com/advisories/ZDI-11-288/
http://www.zerodayinitiative.com/advisories/ZDI-11-289/
http://www.zerodayinitiative.com/advisories/ZDI-11-290/

Deep Links
Links available to Secunia VIM customers