October's Critical IE Cumulative Update Corrects Four Code Execution Flaws
SEVERITY: HIGH
13 October, 2009
SUMMARY:
- This vulnerability affects: Internet Explorer 8 and earlier versions, running on all current version of Windows
- How an attacker exploits it: By enticing one of your users to visit a web page or link containing malicious code
- Impact: In the worst case, the attacker can execute code on your user's computer, gaining complete control of it
- What to do: Deploy the appropriate Internet Explorer patches immediately
EXPOSURE:
In a security bulletin released today as part of its monthly patch update, Microsoft describes four 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).
Although the four vulnerabilities differ technically, they share the same general scope and impact. Most of them involve memory corruption flaws having to do with how IE handles various HTML objects or data streams. If an attacker can lure one of your users to a web page containing malicious web code, he can exploit 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.
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.
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, you should download and install the IE cumulative patch as soon as possible.
SOLUTION PATH:
These patches fix serious issues. You should download, test, and deploy the appropriate IE patches as soon as possible.
* Note: These flaws do not affect Windows Server 2008 administrators who installed using the Server Core installation option.
STATUS:
Microsoft has released patches to fix these vulnerabilities.
REFERENCES:
MS Security Bulletin MS09-054
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