Software Engineering Institute

The Microsoft virtual machine (Microsoft VM) enables Java programs to run on Windows platforms. The Microsoft VM is included in most versions of Windows and Internet Explorer.

System properties provide the means through which Java programs can query the operating system and gain detailed information about the system on which they are running. The Microsoft VM allows access to the user.dir system property from untrusted Java programs.

A malicious Java applet that was designed to exploit this vulnerability could be hosted on an attacker's web page or delivered via HTML email.

A malicious program could exploit this vulnerability to disclose the path to the current working directory of the Microsoft VM-enabled application. Information contained in this path could provide additional information about the system, such as the user's username, that could be leveraged in other attacks.

Apply a patch from the vendor

Microsoft has issued Security Bulletin MS02-069 addressing this vulnerability. Users are encouraged to follow the instructions outlined in that bulletin and apply the patches that it refers to.

Workarounds

Disable Java

If the ability to run Java applets is not required or desired, configure your web browser to not execute them. Information about disabling Java in various web browsers can be found here.

Note that disabling Java in your web browser may not mitigate this vulnerability for Java programs that are invoked via another method.