Researchers have discovered a new flaw in Mozilla's Firefox browser that can be exploited by attackers to take over a user's computer, as long as the victim also has Internet Explorer (IE) installed.
The flaw can be used to execute arbitrary code when a user visits a malicious website using IE, which then opens a vulnerable Firefox, according to Secunia.
Secunia ranked the flaw as "highly critical," meaning it can be exploited to execute arbitrary code.
A Mozilla representative could not immediately be reached for comment.
According to a post on xs-sniper.com, Rios, Mcfeters and Dube said that the flaw can be exploited when parameters that are part of firefoxurl: are passed to Firefox.exe as options, without validation.
In an advisory released today, FrSIRT ranked the flaw as "critical."
Researcher Thor Larholm detailed a proof-of-concept exploit for the flaw on his website. He later commented that Firefox URL handler was only added to the browser in version 18.104.22.168 so that it would be compatible with Vista.