Firefox Security Holes

Firefox 3.0.11 Plugs 11 Security Holes

Severity: Medium

12 June, 2009

Summary:

• This vulnerability affects: Firefox 3.0.10 (and previous versions) for Windows, Linux, and Macintosh
• How an attacker exploits it: Multiple vectors of attack, including enticing one of your users to visit a malicious web page
• Impact: Various results; in the worst case, an attacker executes code on your user’s computer, gaining complete control of it
• What to do: Upgrade to Firefox 3.0.11

Exposure:

Late Yesterday, the Mozilla Foundation released Firefox 3.011, fixing nearly a dozen vulnerabilities (we based our count on CVE-IDs) in their popular web browser. We summarize some of the worst vulnerabilities below:

• Memory corruption vulnerabilities (2009-024). Firefox suffers from three crash bugs, which corrupt memory. Mozilla’s alert shares few details about these memory corruption flaws, but it does say the flaws lie within Firefox’s browser and JavaScript engines. The flaws also affect some other Mozilla-based products, like Thunderbird. Mozilla presumes that, with enough effort, attackers could exploit some of these memory corruption flaws to run arbitrary code on a victim’s computer. To do so, an attacker would first have to trick one of your users into visiting a maliciously crafted web page. If your user took the bait, the attacker could execute malicious code on that user’s machine, with that user’s privileges. If the user happened to be a local administrator or had root privileges, the attacker would gain total control of the victim’s computer.
  Mozilla Impact rating: Critical
• JavaScript chrome privilege escalation (2009-032). Firefox suffers from a vulnerability that could allow scripts from a web page to run with elevated privileges. By enticing one of your users to a malicious web site, a remote attacker could exploit this flaw to execute code on your computer with Firefox’s chrome privileges. According to Mozilla, code running with chrome privileges is allowed to do everything, unlike normal web content, which is restricted in several ways. That means attackers could exploit this flaw to execute the same code as your user. If your user has local administrative privileges, the attacker could leverage this flaw to gain complete control of the user’s machine.
  Mozilla Impact rating: Critical
• Race Condition vulnerability while accessing HTML object (2009-028). Firefox suffers from a complex race condition vulnerability when accessing a particular HTML object (JSobject). By enticing your user to a specially crafted web site, a remote attacker could exploit this race condition to potentially execute code on your user’s computer with their privileges. If your user has local administrative, or root privileges, the attacker could leverage this flaw to gain complete control of your user’s machine.
  Mozilla Impact rating: Critical