CVE-2025-9491 in Windows
Summary
by MITRE • 08/26/2025
Microsoft Windows LNK File UI Misrepresentation Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Windows. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the handling of .LNK files. Crafted data in an .LNK file can cause hazardous content in the file to be invisible to a user who inspects the file via the Windows-provided user interface. An attacker can leverage this vulnerability to execute code in the context of the current user. Was ZDI-CAN-25373.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 03/22/2026
This vulnerability represents a critical security flaw in Microsoft Windows operating systems that exploits the way .LNK files are displayed and processed within the graphical user interface. The issue stems from a UI misrepresentation mechanism that allows malicious actors to craft .LNK files with deceptive content that appears benign to users while harboring executable code. This vulnerability falls under the category of user interface deception and falls into the CWE-693 category of Protection Mechanism Failure, where the system fails to properly validate or represent file content to end users. The flaw specifically affects how Windows handles the display of .LNK file properties and metadata, creating a scenario where the visual representation of file attributes does not accurately reflect the underlying file structure.
The technical implementation of this vulnerability occurs when a Windows system processes a maliciously crafted .LNK file that contains hidden or obfuscated payload data. The system's graphical interface displays misleading information about the file's contents, making it appear as though the file is safe to execute while actually containing code that can be executed with the privileges of the current user. This misrepresentation allows attackers to bypass user awareness mechanisms that would normally prevent execution of suspicious files. The vulnerability is particularly dangerous because it leverages the trust users place in Windows file dialogs and the visual confirmation provided by the operating system's file browsing interface. The attack vector requires user interaction through either visiting a malicious webpage that hosts the .LNK file or directly opening the crafted file, making it a prime example of a social engineering attack that combines file system manipulation with user interface deception.
From an operational impact perspective, this vulnerability creates significant risk for organizations as it allows remote code execution without requiring administrative privileges or complex exploitation techniques. The attack surface is broad since .LNK files are commonly used in various contexts including email attachments, web downloads, and removable media. The vulnerability can be exploited in multiple scenarios such as phishing campaigns where attackers embed malicious .LNK files in email attachments or web content, or through malicious websites that automatically download and execute these files when users browse to them. This vulnerability directly maps to the ATT&CK technique T1204.002 which involves user execution through malicious file content, and represents a significant escalation path for attackers who can leverage this flaw to gain initial access to systems. The execution context of the current user means that the attack can potentially be used to establish persistence, escalate privileges, or access sensitive data depending on the user's access level and the system's configuration.
Organizations should implement multiple layers of defense to mitigate this vulnerability including immediate patch deployment for affected Windows versions, enhanced security awareness training for users to recognize suspicious file behavior, and network-based protections such as web filtering and email security solutions that can detect and block malicious .LNK files. System administrators should also consider implementing additional file execution restrictions and monitoring for unusual .LNK file activity. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how seemingly minor UI representation flaws can have significant security implications. Organizations should also review their incident response procedures to ensure they can quickly identify and respond to potential exploitation attempts involving .LNK file manipulation. The security community should remain vigilant for similar vulnerabilities in file handling mechanisms and user interface components that could be exploited in similar ways to compromise system integrity and user security.