Microsoft Issues 'fix it' To Close Internet Explorer 0-day Vulnerability

Last few days the whole cyber world have gone through with so many drama of Internet Explorer's security bug, as researchers have unveiled four active exploits of a zero-day vulnerability in the browser. As expected the software giant Microsoft has released an emergency fix to get rid of these major security issues. Microsoft released a “fix it” tool for a critical security flaw in most versions of Internet Explorer 6, 7, 8 and 9 that hackers have been exploiting to break into Windows systems. 

The company said it expects to issue an official patch (MS12-063) for the vulnerability on Friday, Sept. 21. "While we have only seen a few attempts to exploit this issue, impacting an extremely limited number of people, we are taking this proactive step to help ensure Internet Explorer customers are protected and able to safely browse online," said Yunsun Wee, director of Microsoft Trustworthy Computing in a statement. The zero-day in IE 6-9 is a use-after-free memory corruption vulnerability,similar to a buffer overflow, that would enable an attacker to remotely execute code on a compromised machine. The original exploit payload dropped the PoisonIvy remote access Trojan (RAT) via a corrupted Flash movie file. The latest payload discovered dropped the PlugX RAT via the same corrupted Flash movie, Blasco said. He also said the new exploits are the work of the Chinese hacker group Nitro, the same group behind a pair of Java zero-day exploits disclosed in August.


Blasco also said the new exploits appear to be targeting defense contractors in the United States and India.
Microsoft recommended several workarounds Tuesday morning before announcing its intention to send out a FixIt.

• Setting Internet and local Internet security zone settings to high, which would block ActiveX Controls and Active Scripting in both zones
• Configure IE to prompt the user before running Active Scripting, or disable Active Scripting in both zones
• Use of Microsoft's Enhanced Mitigation Experience Toolkit provides mitigations as well, and would not impact website usability, as both of the first two options might.
• Microsoft also said that IE running on Windows Server 2003, 2008 and 2008R2 runs in a restricted mode that mitigates the vulnerability. Outlook, Outlook Express and Windows Mail also open HTML messages in a restricted zone, mitigating the vulnerabilty but should a user click a link in a message, they could still be vulnerable to exploit.