CVE-2015-2465

Vulnerability

The Windows Shell component in multiple Microsoft Windows versions does not properly constrain impersonation levels. Affected editions include Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT Gold and 8.1, and Windows 10 [1]. This flaw allows a locally authenticated attacker to bypass intended security restrictions by running a specially crafted application that triggers improper impersonation behavior.

Exploitation

An attacker must have local access to the system and be able to execute arbitrary code as a low-privileged user. No user interaction is required beyond running the crafted application. The attacker can exploit the vulnerability by launching a program that manipulates the impersonation mechanism to gain higher privileges [1].

Impact

Successful exploitation results in elevation of privilege, allowing the attacker to execute code with elevated integrity levels. This could lead to full control of the affected system, including the ability to install programs, view, change, or delete data, and create new accounts with full user rights [1].

Mitigation

Microsoft released security update MS15-080, which addresses the vulnerability by correcting how the Windows Shell validates impersonation levels. The update was made available on August 11, 2015, for all affected software versions [1]. No workarounds are documented in the advisory. Applying the update is the only known mitigation.