Microsoft has recently released a patch to fix the fixed vulnerability discovered  nine months back at last year’s Pwn2Own hacking contest .Just hours after the release of patch the exploit can take advantage of the bug with Metasploit, Microsoft confirmed the existence of an unpatched vulnerability in Windows.

The editor, who is working on a patch, however, did not intend to engage in an urgent update to correct this flaw. Microsoft, which acknowledged the bug in a security advisor, said that only Windows XP, Vista, Server 2003 and Server 2008 are affected by this vulnerability, but not the latest operating system Windows 7 and Server 2008 R2.

Mentioned first time in Dec. 15 at a security conference held in South Korea, the fault has generated more attention Tuesday when the toolbox open source Metasploit used to facilitate testing of intrusion has yielded a feat designed by the researcher Joshua Drake. According to Metasploit, if successful, attacks can infect computer and introduce malware to extracting information or enroll  in botnet criminals.

The vulnerability has been identified in the Graphics Rendering Engine in Windows, and especially in how it manages the thumbnails of files. In particular, it can be activated when the user views the file manager with a Windows folder with a sticker diverted, or when opening Office documents or view some.

Attackers may send users of malicious Word or PowerPoint documents containing an infected thumbnail, that they are open or even just previewed, would give access to use their PCs, Microsoft said. According to the scenario, hackers can hijack PCs if they manage to push users to display a thumbnail infected on a folder or a shared network drive, or even via a system of sharing files online WebDAV.

This vulnerability allows remote code execution. An attacker who successfully exploited this could take complete control of an affected system, “the report said Microsoft security.”To exploit the vulnerability in the color table of the image file, the number of color index is changed to a negative number,” said Johannes Ullrich, director of research at the SANS Institute.

Now the users are advised to wait for a solution from Microsoft. Pending the issuance of a corrective, the publisher recommends a temporary workaround to protect PCs against potential attacks. It is to add more restrictions to the file “shimgvw.dll”, the component that handles the preview images in Windows but requires users to enter a string at a command prompt. It also means that “the media files usually handled by the graphics rendering engine will not be displayed properly,” as indicated by the Microsoft.

Microsoft has just finished the year with its largest patch, and 2011 does not look better,” said Andrew Storms. In 2010, the publisher has reached a record $ 106 security bulletin to address a record number of 266 vulnerabilities.