Mozilla ups Firefox bug threat, slates fix for Feb. 5

by Gregg Keizer

January 30, 2008 —

Mozilla Corp. bumped
up the threat ranking for an unpatched Firefox bug to "high" Tuesday,
but promised a fix is coming in Version 2.0.0.12, now slated for release on
Feb. 5.

The company's head of security, Window Snyder, confirmed that the browser,
when running any of more than 600 add-ons, can be exploited to steal "session
information, including session cookies and session history."

Snyder's acknowledgment followed an update by Gerry Eisenhaur, the researcher
who first reported the Firefox problem. "There seems to be some confusion
about what exactly the severity of this vulnerability is," Eisenhaur said
on his hiredhacker.com blog. "This is not a chrome privilege escalation,
but it [is] worse than just leaking some variables. I created another demo to
read the sessionstore.js file. This will display information regarding your
current session, [including] windows, tabs, cookies, etc."

Last week, when Eisenhaur broached the subject, Mozilla rated the threat as
only "low," but began working on a patch. Yesterday, Snyder said a
patch would be included with Firefox 2.0.0.12, a security update currently scheduled
for a Feb. 5 release.

"Firefox is not vulnerable by default," Snyder added Tuesday. "Only
users that have installed 'flat' packed add-ons are at risk."

Her caveat may be a moot point for most Firefox users, however, since such
add-ons are legion. For example, a partial list posted on Bugzilla,
Mozilla's bug management database, runs to more than 600 Firefox extensions,
including YouTube-It and Foxmarks Bookmark Synchronizer. Snyder urged add-on
authors to update their extensions by packaging them as .jar (Java Archive)
files to make them immune to the vulnerability.

Alternately, Firefox users can install the popular NoScript extension to block
exploits, regardless of which add-ons have been installed.

Computerworld