JavaScript spy creates an e-mail wiretap

A newly identified snooping technology allows someone sending an email to see what the recipient wrote when it is forwarded on to another user, an Internet privacy group announced Monday.

It really is a wiretap and it's "very illegal and very easy to do," said Richard Smith, chief technology officer for the Privacy Foundation based in Denver, in a column he wrote for the non-profit educational and research organization. The vulnerability exists in mail that uses HTML (HyperText Markup Language).

A few lines of JavaScript can be embedded in an email message and allows the recipient's mail to be returned to the original sender. It only works, however, if the recipient's email program is set to read JavaScript.

Smith learned about the email exploit while working on research on Web bugs, an invisible image embedded in a Web page or email that quietly transmits a message back to a remote computer when viewed. He corresponded with Carl Voth, an engineer in British Columbia, who told him about the JavaScript vulnerability. Voth is believed to have discovered the flaw he calls the "reaper exploit" in October 1998.

Computer scientists from the Privacy Foundation have learned that the exploit only works when the recipient is using an HTML/JavaScript-enabled email reader such as Microsoft Corp.'s Outlook, Outlook Express or version 6 of Netscape Communications Corp.'s Web browser package. Eudora, Qualcomm Inc.'s email software, and version 6 of America Online Inc.'s latest client software are not affected as JavaScript is turned off by default. Microsoft's Hotmail and other Web-based email systems automatically remove JavaScript programs from incoming email messages and therefore are not vulnerable.

Smith, in his column, worries that the exploit may be used often and people may try to gain access to information that they normally would not be privileged to see. For example, a user may send a resume via email and then learn what the potential employer thinks about his or her qualifications, Smith writes.

The Privacy Foundation has requested Microsoft and Netscape to turn off JavaScript code by default in all of their email readers. Little use is seen for JavaScript in email, only pitfalls such as viruses, email spam and now the wiretapping problem, Smith said.

Smith's column and further information on the exploit can be viewed at

The Privacy Foundation, in Denver, can be reached at

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