- This vulnerability affects: Internet Explorer 8 and all earlier versions, running on all current versions of Windows
- How an attacker exploits it: By enticing one of your users to visit a malicious web page
- Impact: In the worst case, an attacker can execute code on your user’s computer, gaining complete control of it
- What to do: Deploy the appropriate Internet Explorer patches immediately
In an out-of-cycle security bulletin released today, Microsoft describes nine new vulnerabilities in Internet Explorer (IE) 8.0 and earlier versions, running on all current versions of Windows (including Windows 7 and Windows Server 2008). One of the corrected vulnerabilities includes a critical zero day flaw that attackers have exploited in the wild since at least early March. For more information about this previously reported zero day IE flaw, see our Wire post on the subject.
The nine vulnerabilities differ technically, but seven of them share the same general scope and impact. These seven flaws involve various memory corruption issues having to do with how IE handles certain HTML objects and memory constructs. If an attacker can lure one of your users to a web page containing malicious web code, he could exploit any one of these vulnerabilities to execute code on that user’s computer, inheriting that user’s privileges. Typically, Windows users have local administrative privileges. In that case, the attacker could exploit these flaws to gain complete control of the victim’s computer. The remaining two vulnerabilities are less risky information disclosure flaws.
If you’d like to know more about the technical differences between these flaws, see the “Vulnerability Information” section of Microsoft’s bulletin. Technical differences aside, all of these IE flaws pose significant risk – especially, the zero day vulnerability that attackers have been exploiting in the wild. You should download and install this emergency IE patch immediately.
Keep in mind, today’s attackers commonly hijack legitimate web pages and booby-trap them with malicious code. They do this via hosted web ads or through SQL injection attacks. Even recognizable and authentic websites could pose a risk to your users if hijacked in this way.
These patches fix serious issues. You should download, test, and deploy the appropriate IE patches immediately, or let Windows Automatic Update do it for you.
- Internet Explorer 5.01
- Internet Explorer 6.0
- Internet Explorer 7.0
- Internet Explorer 8.0
* Note: These flaws do not affect Windows Server 2008 administrators who installed using the Server Core installation option.
For All WatchGuard Users:
These attacks travel as normal-looking HTTP traffic, which you must allow if your network users need to access the World Wide Web. Therefore, the patches above are your best solution.
Microsoft has released patches to fix these vulnerabilities.