CVE-2024-2849: Simple File Manager RCE Vulnerability

CVE-2024-2849 Overview

A critical unrestricted file upload vulnerability has been identified in SourceCodester Simple File Manager version 1.0. This vulnerability allows remote attackers to upload arbitrary files to the affected web application by manipulating the photo argument parameter, potentially leading to complete system compromise. The exploit has been publicly disclosed, increasing the risk of exploitation by malicious actors.

Critical Impact

This unrestricted file upload vulnerability enables remote attackers to upload malicious files without authentication, potentially leading to remote code execution, data theft, and complete server compromise.

Affected Products

• Ganeshrkt Simple File Manager Web App version 1.0
• SourceCodester Simple File Manager 1.0

Discovery Timeline

• 2024-03-23 - CVE-2024-2849 published to NVD
• 2025-02-18 - Last updated in NVD database

Technical Details for CVE-2024-2849

Vulnerability Analysis

This vulnerability exists due to improper validation of file uploads in the Simple File Manager web application. The application fails to properly validate or restrict file types when processing the photo parameter, allowing attackers to upload files with arbitrary content and dangerous file extensions. This type of vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) is particularly severe because it can directly lead to remote code execution when combined with a web-accessible upload directory.

The vulnerability can be exploited remotely without requiring authentication or user interaction, making it highly dangerous for any exposed deployment.

Root Cause

The root cause of CVE-2024-2849 is the absence of proper file type validation in the file upload functionality. The application does not implement adequate checks for:

• File extension validation against an allowlist
• MIME type verification
• File content inspection (magic bytes)
• Filename sanitization

This allows an attacker to bypass any client-side restrictions and upload executable files such as PHP web shells directly to the server.

Attack Vector

The attack can be initiated remotely over the network. An attacker can craft a malicious HTTP request targeting the vulnerable file upload endpoint, manipulating the photo parameter to upload a file containing malicious code. Once uploaded, if the file is stored in a web-accessible directory without execution restrictions, the attacker can access the uploaded file directly to execute arbitrary code on the server.

The attack flow typically involves:

1. Identifying the vulnerable upload endpoint
2. Crafting a request with a malicious file (e.g., PHP web shell) disguised or directly uploaded via the photo parameter
3. Uploading the malicious file to the server
4. Accessing the uploaded file to trigger code execution

Since no verified exploit code is available, security teams should consult the GitHub Issue Discussion and VulDB entry for additional technical details on exploitation methods.

Detection Methods for CVE-2024-2849

Indicators of Compromise

• Unusual files with executable extensions (.php, .phtml, .php5, .phar) appearing in upload directories
• Web server access logs showing requests to newly uploaded files in upload directories
• Unexpected outbound connections from the web server
• Presence of web shell signatures in uploaded files

Detection Strategies

• Monitor file upload directories for newly created files with executable extensions
• Implement web application firewall (WAF) rules to detect file upload attacks and web shell uploads
• Deploy file integrity monitoring (FIM) on web-accessible directories
• Analyze HTTP request logs for suspicious file upload activity targeting the photo parameter

Monitoring Recommendations

• Enable detailed logging on the web application and web server
• Configure SIEM alerts for file creation events in upload directories
• Monitor for POST requests with multipart form data containing suspicious file extensions
• Review web server error logs for signs of attempted code execution

How to Mitigate CVE-2024-2849

Immediate Actions Required

• Immediately restrict or disable the file upload functionality until a patch is applied
• Remove or restrict network access to the vulnerable Simple File Manager application
• Audit upload directories for any suspicious or unauthorized files
• Implement web server configuration to prevent execution of uploaded files

Patch Information

At the time of this writing, no official patch has been released by the vendor for CVE-2024-2849. Organizations are strongly advised to monitor the vendor's release channels and VulDB for updates. Given the critical nature of this vulnerability, consider replacing the affected application with a more secure alternative if no patch becomes available.

Workarounds

• Configure the web server to prevent script execution in upload directories
• Implement strict file extension allowlists at the server level (only allow image extensions like .jpg, .png, .gif)
• Deploy a web application firewall (WAF) with rules to block malicious file uploads
• Rename uploaded files to remove original extensions and store them outside the web root

# Apache configuration to prevent script execution in upload directory
<Directory "/var/www/html/uploads">
    php_admin_flag engine off
    Options -ExecCGI
    RemoveHandler .php .phtml .php5 .php7 .phar
    AddType text/plain .php .phtml .php5 .php7 .phar
</Directory>