Microsoft on Tuesday warned users of a vulnerability in 64-bit versions of Windows 7 and Windows Server 2008 R2 that could expose users to malware attacks.
Exploitation of the bug in the Canonical Display Driver
would most likely cause vulnerable machines only to reboot, Microsoft spokesman Jerry Bryant said in a blog post. But it could also be abused to silently install malware, although attackers first would have to bypass memory randomization protections baked in to the operating systems to prevent code execution attacks, he added.
The vulnerability stems from the Canonical Display Driver's failure to properly parse information copied from user mode to kernel mode. Malicious hackers could exploit it by tricking a victim into viewing a booby-trapped image file on a website or in email. The driver emulates the Windows XP display driver for interactions with earlier Windows graphics engines.
Bryant said a patch would be forthcoming, but didn't say when. In the meantime, users can prevent attacks by disabling the Windows Aero Theme. To turn it off, choose Start > Control Panel and click on Appearance and Personalization. Then click on Change the Theme. Then select one of the Basic and High Contrast Themes.