Mozilla Foundation Security Advisory 2006-50

JavaScript engine vulnerabilities

Announced
July 25, 2006
Reporter
Mozilla community
Impact
Critical
Products
Firefox, SeaMonkey, Thunderbird
Fixed in
  • Firefox 1.5.0.5
  • SeaMonkey 1.0.3
  • Thunderbird 1.5.0.5

Description

Continuing our security audit of the JavaScript engine, Mozilla developers found and fixed several potential vulnerabilities.

Igor Bukanov and shutdown found additional places where an untimely garbage collection could delete a temporary object that was in active use (similar to MFSA 2006-01 and MFSA 2006-10). Some of these may allow an attacker to run arbitrary code given the right conditions.

Georgi Guninski found potential integer overflow issues with long strings in the toSource() methods of the Object, Array and String objects as well as string function arguments.

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

Garbage collection issues discovered by Igor Bukanov and shutdown:

Integer overflow issues found by Georgi Guninski: