Security researcher Mariusz Mlynski, via TippingPoint's
Pwn2Own contest, reported that it is possible for untrusted web content to load
a chrome-privileged page by getting JavaScript-implemented WebIDL to call
window.open()
. A second bug allowed the bypassing of the
popup-blocker without user interaction. Combined these two bugs allow an
attacker to load a JavaScript URL that is executed with the full privileges of
the browser, which allows arbitrary code execution.
In general this flaw cannot be exploited through email in the Thunderbird and Seamonkey products because scripting is disabled, but is potentially a risk in browser or browser-like contexts.