Internet Explorer allows remote attackers to bypass zone restrictions to inject and execute arbitrary programs by creating a popup window and inserting ActiveX object code with a "data" tag pointing to the malicious code, which Internet Explorer treats as HTML or Javascript, but later executes as an HTA application, a different vulnerability than CVE-2003-0532, and as exploited using the QHosts Trojan horse (aka Trojan.Qhosts, QHosts-1, VBS.QHOSTS, or aolfix.exe).

Internet Explorer 5.01 SP3 through 6.0 SP1 does not properly determine object types that are returned by web servers, which could allow remote attackers to execute arbitrary code via an object tag with a data parameter to a malicious file hosted on a server that returns an unsafe Content-Type, aka the "Object Type" vulnerability.