The update, Mozilla's first of the year, fixed critical flaws in Firefox's handling of web browsing history, privilege escalation, cross-site scripting, as well as other vulnerabilities that can cause crashes with memory corruption.
The web-browsing history flaw can be exploited to run arbitrary code on a victim's PC, and the privilege escalation vulnerability can be violated to inject script onto a third-party site, according to advisories released by Mozilla on Thursday.
Mozilla also fixed a “high” danger flaw in the way Firefox handles URI schemes. The vulnerability can be exploited to steal the contents of the browser's sessionstore.js file, which contains session cookie data and information about open web pages, according to the Mountain View, Calif.-based company.
Three “moderate” and three “low” risk flaws were also fixed on Thursday. The patches, announced Friday on the blog of Window Snyder, Mozilla chief security something-or-other, will be available to Firefox users via automatic update notification by Saturday evening.
Secunia, a Copenhagen-based vulnerability monitoring organization, called the batch of flaws “highly critical” on Friday, meaning that some of the issues can be exploited for arbitrary code execution, but no exploits have been seen in the wild.
FrSIRT, the French Security Incident Response Team, on Friday ranked the group of issues as “critical,” meaning that they can be exploited to take over a PC.
The patches are Mozilla's first critical fixes since the company upgraded Thunderbird, the developer's email client, last December.
The most recent mass-patch for Mozilla products was issued last October, when eight flaws were patched.