Windows 7 UAC vulnerability
Posted: February 9th, 2009 | Tags: Microsoft, Security holes, Vulnerabilities |The release of Windows Vista has brought the new possibility intended for security of the computer – the User Account Control (UAC). However so useful possibility became at first the excellent reason of criticism to the operating system that has been linked to huge number of the warning diagnostics, which many users have considered irritating and simply disabled.
However the reduced number of messages from UAC in Windows 7 as it has appeared, still is not an advantage at all. In Windows 7 Microsoft has decided to change the policy and already in beta-versions of the future operating system began to offer less irritating UAC. Now it can receive an absolutely return estimation since blogger Long Zheng (Long Zheng), the leader of blog Start Something, has in details described the concept of attack against new UAC in Windows 7.
According to Zheng, presence of the concept of attack is the certificate of that the new approach to UAC in Windows 7, more pleasant for some, inherently is insecure. “Changes in UAC in Windows 7 (beta) fulfilled to make the control less irritating, have unpremeditatedly cleared away path for simple, but skilful detour which fulfils disconnecting UAC without interaction with the user”, the blogger has declared.
The matter is that by default UAC in Windows 7 is customised on a mode “Notify me only when programs try to make changes to my computer” and “Don’t notify me when I make changes to Windows settings”. In this mode, whether to define is the program Windows part, the operating system uses the security certificate, and the control panel has such certificate. In other words – changes in the control panel do not call warning appearance. An Achilles’ heel of such approach, under the description of Zheng, that UAC is the certificated program is and consequently changes in it also are entrusted – even if changes consists in disconnecting most UAC.
Therefore it is possible to disable UAC without user’s consent, and it is possible to guess consequences of similar disconnecting only. As proof of fidelity of the opinion of Zheng has presented script VBScript which by means of a shortcut key allows to select UAC and then to disable it. Attack works against any user with the management rights (as the password of the manager is requested of standard users at change of customisations UAC). “Soon we realise that consequences even will be worse, than we initially thought. After modification in UAC you can automate reboot, add the program in a user’s folder of a StartUp and because UAC now it is switched off, working with the complete management rights, be ready to complete chaos”, has declared Zheng.
He has added what to correct it it is possible, having translated UAC in a mode secure desktop, in not dependences on its current state. It should prevent the main attempts of attack though is not panacea. Zheng also has suggested Microsoft to release appropriate correction as soon as possible. In too time the company of Microsoft, apparently, how many is not excited with the given theme. Under the statement of the largest program manufacturer, vulnerability is “deliberate” and consequently will not vary to release.
Leave a Reply