Serious Windows 7 Flaws Unearthed

Microsoft announced on Tuesday that its newest operating system Windows 7 can be vulnerable to users in terms of code execution and denial-of-service attacks. The vulnerability of Windows 7 and Windows Server 2008 R2 has been discussed before Microsoft issued the advisory. Although, the company claims that no attack due to this Windows flaws has been reported so far. The flaw was found in the Canonical Display Driver (cdd.dll), which is used by desktop composition to mix the Windows Graphics Device Interface (GDI) and DirectX drawing.

Microsoft also thinks that  chances are high if an attacker can successfully exploit this vulnerability, it can result the affected system to stop responding and automatically restart. The company assured that they are going to fix the problem once the investigation is complete. By this time, affected Windows 7 or Windows 2008 R2 users should disable the Windows Aero Theme to prevent the issue from being exploited.

Code execution, while possible in theory, would be very difficult due to memory randomization both in kernel memory and via Address Space Layout Randomization (ASLR). Additionally, this vulnerability only affects Windows systems if they have the Aero theme installed; Aero is not switched on by default in Windows Server 2008 R2, nor does 2008 R2 include Aero-capable graphics drivers by default.

Please, follow the steps to disable the Aero theme:

1. Click Start, select the Control Panel, and then click on Appearance and Personalization.
2. Under the Personalization category, click on Change the Theme.
3. Scroll to the bottom of the listed themes and select one of the available Basic and High Contrast Themes.