Mozilla Foundation Security Advisory 2006-47

Native DOM methods can be hijacked across domains

Announced
July 25, 2006
Reporter
Thor Larholm
Impact
High
Products
Firefox, SeaMonkey, Thunderbird
Fixed in
  • Firefox 1.5.0.5
  • SeaMonkey 1.0.3
  • Thunderbird 1.5.0.5

Description

A malicious page can hijack native DOM methods on a document object in another domain, which will run the attacker's script when called by the victim page. This could be used to steal login cookies, password, or other sensitive data on the target page, or to perform actions on behalf of a logged-in user.

Access checks on all other properties and document nodes are performed correctly. This cross-site scripting (XSS) attack is limited to pages which use standard DOM methods of the top-level document object, such as document.getElementById(). This includes many popular sites, especially the newer ones that offer rich interaction to the user.

This vulnerability was introduced during Firefox 1.5 development, it does not affect Firefox 1.0 or Mozilla Suite 1.7

Thunderbird shares the browser engine with Firefox and would be vulnerable if JavaScript were to be enabled in mail. This is not the default setting and we strongly discourage users from enabling JavaScript in mail.

Workaround

Disable JavaScript until you can upgrade to a fixed version. Do not enable JavaScript in mail clients such as Thunderbird.

References