Mozilla Foundation Security Advisory 2006-15

Privilege escalation using a JavaScript function's cloned parent

Announced

April 13, 2006

Reporter

shutdown

Impact

Critical

Products

Firefox, Mozilla Suite, SeaMonkey, Thunderbird

Fixed in

• Firefox 1.0.8
• Firefox 1.5
• Mozilla Suite 1.7.13
• SeaMonkey 1
• Thunderbird 1.0.8
• Thunderbird 1.5

Description

shutdown discovered it was possible to use the Object.watch() method to access an internal function object (the "clone parent") which could then be used to run arbitrary JavaScript code with full permission. This could be used to install malware such as password sniffers or viruses.

In pre-release versions of Firefox 1.5 the same technique could be applied to the Array generic methods introduced in that release.

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

Workaround

Disable JavaScript until you can upgrade to a fixed version.

References

Exploit code and details embargoed during the active update period.

• https://bugzilla.mozilla.org/show_bug.cgi?id=313370
• https://bugzilla.mozilla.org/show_bug.cgi?id=313684
  CVE-2006-1734