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

1) An error in the ActiveX control for streaming video (msvidctl.dll) when initialising the control can be exploited to cause a stack-based buffer overflow by supplying a specially crafted data file when embedding the object.

The vulnerability is confirmed in Microsoft Windows XP SP3 and is also reported by Microsoft in Windows Server 2003.

NOTE: The vulnerability is currently being actively exploited.

2) An unspecified error in the ActiveX control for streaming video (msvidctl.dll) can be exploited to corrupt memory.

Successful exploitation of the vulnerabilities allows execution of arbitrary code when a user e.g. visits a malicious website.

Solution
Microsoft has issued updates, which set the kill-bit for the affected ActiveX control.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) Reported as a 0-day (also reported by Ryan Smith and Alex Wheeler, IBM X-Force).
2) Robert Freeman, IBM X-Force.

Changelog
Further details available to Secunia VIM customers

Original Advisory
Microsoft:
http://www.microsoft.com/technet/security/advisory/972890.mspx
http://blogs.technet.com/srd/archive/2009/07/06/new-vulnerability-in-mpeg2tunerequest-activex-control-object-in-msvidctl-dll.aspx
http://blogs.technet.com/msrc/archive/2009/07/06/microsoft-security-advisory-972890-released.aspx

MS09-032 (KB973346):
http://www.microsoft.com/technet/security/Bulletin/MS09-032.mspx

IBM X-Force:
http://www.iss.net/threats/329.html

KingSoft Internet Security Blog:
http://blog.duba.net/read.php/225.htm
http://blog.duba.net/read.php/226.htm

Alternate/detailed remediation
Further details available in Customer Area

Deep Links
Links available to Secunia VIM customers