A remote code execution vulnerability exists when the Windows Shell does not properly validate file paths. An attacker who successfully exploited this vulnerability could run arbitrary code in the context of the current user. If the current user is logged on as an administrator, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with elevated privileges. Users whose accounts are configured to have fewer privileges on the system could be less impacted than users who operate with administrative privileges. To exploit the vulnerability, an attacker must entice a user to open a specially crafted file. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and then convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) that contains a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force a user to visit the website. Instead, an attacker would have to convince a user to click a link and open the specially crafted file. This security update addresses the vulnerability by ensuring the Windows Shell properly validates file paths.