Remote compromise via content-defined setter on object prototypes

Remote compromise via content-defined setter on object prototypes

Announced

June 1, 2006

Reporter

Paul Nickerson, moz_bug_r_a4

Impact

Critical

Products

Firefox, SeaMonkey, Thunderbird

Fixed in

• Firefox 1.5.0.4
• SeaMonkey 1.0.2
• Thunderbird 1.5.0.4

Description

Paul Nickerson discovered that content-defined setters on an object prototype were getting called by privileged UI code, and moz_bug_r_a4 was able to develop an exploit PoC that demonstrated that the higher privilege level could be passed along to the content-defined attack code.

Thunderbird shares the browser 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 an upgraded version is installed. Do not enable JavaScript in mail clients such as Thunderbird.

References

Exploit details withheld until sufficient time has passed to give users a chance to upgrade

• https://bugzilla.mozilla.org/show_bug.cgi?id=330773
• CVE-2006-2776