Microsoft Internet Explorer 5.0 for Windows 2000/Windows 95/Windows 98/Windows NT 4/Internet Explorer 4.0.1 for Windows 98/Windows NT 4.0 hhopen OLE Control Buffer Overflow Vulnerability
source: https://www.securityfocus.com/bid/669/info
There is a buffer overflow in the 1.0.0.1 version of the hhopen OLE control (hhopen.ocx) that ships with some versions of Internet Explorer. This control is marked 'Safe for Scripting' . Arbitrary commands may be executed if the OLE control is run in a malicious manner.
HHOPEN:
This control is a little more difficult to exploit, as the
RET address is in the middle of the string, and once again
there is no easy way to RET to our code, so I have RET'd to
ExitProcess directly instead. In this case, OpenHelp is the
vulnerable method, and the exploit is possible when the
method is called with a valid help file, and a long Help
Section.