IE Security Flaw Could Enable Remote Code Execution

Although Internet Explorer has been retired, some of its underlying components are still present in many Windows applications. Security researchers have now demonstrated how these legacy components can be abused to turn simple user actions into remote code execution attacks.

The issue involves the Internet Explorer WebBrowser control, a component still embedded in various applications built with technologies such as .NET, Visual Basic, and C++. Because it continues to inherit Internet Explorer’s security behavior, attackers may be able to abuse it to execute malicious code on a victim’s system.

How the Attack Works

Researchers found that the WebBrowser control still follows Internet Explorer’s security zone model, which grants additional privileges to trusted locations such as localhost and local files.

This becomes dangerous when desktop applications expose web interfaces through localhost. If an attacker finds a vulnerability such as cross-site scripting (XSS) in one of these applications, they may be able to move from a remote web page into a more trusted local environment.

The attack chain can involve:

Exploiting a vulnerable localhost application
Downloading malicious files without standard security warnings
Opening local files through the WebBrowser control
Executing scripts in a trusted local context
Launching commands through insecure ActiveX components

Researchers demonstrated that malicious files downloaded through certain localhost scenarios may not receive Microsoft’s Mark-of-the-Web (MOTW) protection. Without this security label, Windows may not display its usual warnings when potentially dangerous content is executed.

Multiple Paths to Code Execution

The research also revealed several additional techniques that attackers could use to increase the chances of compromise.

Potential attack methods include:

Abusing ActiveX components to launch programs
Using media playlist files to leak NTLM hashes
Exploiting ClickOnce and Office-related file formats
Using clickjacking to trick users into opening malicious files
Abusing drag-and-drop functionality to execute shortcuts

In some proof-of-concept demonstrations, attackers used invisible frames to disguise malicious file interactions. A victim might believe they are clicking on a normal webpage when they are actually interacting with local files or applications.

Researchers also showed how malicious shortcuts could be disguised with trusted-looking icons and placed in locations where users are likely to interact with them.

Why Legacy Components Remain a Risk

The findings highlight a common cybersecurity challenge: retired software components can continue creating security risks long after the original product is no longer supported.

Many organizations still rely on applications that use the Internet Explorer WebBrowser control behind the scenes. As long as these components remain active, attackers may continue searching for ways to abuse them.

Security experts recommend that organizations: