Software Engineering Institute

A vulnerability exists in the way that Microsoft Internet Explorer (IE) handles <OBJECT> tags. If the CLASSID (CLSID) is unrecognized, then Internet Explorer will execute arbitrary commands specified through the CODEBASE property with a local path and filename. This allows an attacker to execute any command that is already present on the victim's machine.

An attacker could create an HTML web page that includes an <OBJECT> tag to a local program on the victim's machine. When a victim using IE visits the malicious site, the commands specified will be executed. In conjunction with scripting, or other vulnerabilities, an attacker can execute multiple commands in sequence.

An attacker can execute arbitrary commands on the system with the privileges of the current user. It should be noted that arguments cannot be specifed to the command(s) being executed. This limits the effectiveness of this vulnerability on default installations of Microsoft Windows.

Apply the patch referenced in MS02-047 or a more recent cumulative patch.
This issue is partially addressed by MS02-015. The patch in MS02-015 prevents objects in the Internet Zone from executing local commands via the CODEBASE property. The patch does not, however, prevent objects in the Local Machine Zone from executing commands this way. Other cross domain vulnerabilities, such as VU#711843 and VU#728563, allow untrusted script to execute in the Local Machine Zone, where the script could instantiate objects that use the CODEBASE property to execute local programs. The patch referenced in MS02-047 provides a more complete solution. There remain cases, however, in which script executing in the Local Machine Zone is permitted to execute commands via the CODEBASE property.