Mozilla Foundation Security Advisory 2008-59

Script access to .documentURI and .textContent in mail

November 19, 2008
Boris Zbarsky
SeaMonkey, Thunderbird
Fixed in
  • SeaMonkey 1.1.13
  • Thunderbird


Mozilla developer Boris Zbarsky reported that a malicious mail message might be able to glean personal information about the recipient from the mailbox URI (such as computer account name) if the mail recipient has enabled JavaScript in mail. If a malicious mail is forwarded "in-line" to a recipient who has enabled JavaScript, then comments added by the forwarder could be accessed by scripts in the message and potentially revealed to the original malicious author if that message has also been allowed to load remote content.

Scripts in mail messages no longer have access to the DOM properties .documentURI and .textContent.

Thunderbird is only vulnerable to this issue if JavaScript is enabled in mail. This is not the default setting and we strongly discourage users from running JavaScript in mail.


Disable JavaScript until a version containing these fixes can be installed.