CVE-2025-8255: Exam Form Submission RCE Vulnerability

CVE-2025-8255 Overview

A critical unrestricted file upload vulnerability has been identified in code-projects Exam Form Submission version 1.0. The vulnerability exists in the /register.php file where the manipulation of the image argument allows attackers to upload arbitrary files without proper validation. This flaw enables remote attackers to potentially execute malicious code on the target system by uploading crafted files through the registration functionality.

Critical Impact
Remote attackers can exploit this unrestricted file upload vulnerability to upload malicious files, potentially leading to remote code execution, server compromise, and unauthorized access to sensitive data.

Affected Products

code-projects Exam Form Submission 1.0

Discovery Timeline

2025-07-28 - CVE CVE-2025-8255 published to NVD
2025-07-31 - Last updated in NVD database

Technical Details for CVE-2025-8255

Vulnerability Analysis

This vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type) and CWE-284 (Improper Access Control). The /register.php endpoint in the Exam Form Submission application fails to properly validate file uploads through the image parameter. Without adequate file type verification, extension filtering, or content inspection, attackers can upload files with dangerous extensions such as .php, .phtml, or other executable formats.

The vulnerability can be exploited remotely without authentication, as the registration functionality is typically accessible to unauthenticated users. Upon successful upload of a malicious file, an attacker could navigate to the uploaded file's location on the server to trigger execution, potentially gaining a web shell or establishing persistent access to the compromised system.

Root Cause

The root cause of this vulnerability is the absence of proper input validation and security controls on the file upload functionality within /register.php. The application does not implement:

File type validation based on content (magic bytes)
Whitelist-based file extension filtering
Proper access controls on upload directories
Content-Type header verification

This allows the image parameter to accept arbitrary file types, including server-side executable scripts.

Attack Vector

The attack is initiated remotely over the network. An attacker can craft a malicious HTTP POST request to the /register.php endpoint, including a weaponized file in the image parameter. The attack requires no authentication or user interaction, making it trivially exploitable.

The attacker would typically:

Create a malicious PHP web shell or backdoor script
Submit a registration form with the malicious file as the profile image
Locate the uploaded file in the application's upload directory
Access the uploaded file via web browser to execute the payload

Since no verified proof-of-concept code is available for this vulnerability, organizations should refer to the GitHub CVE Issue Discussion and VulDB #317843 Details for additional technical information.

Detection Methods for CVE-2025-8255

Indicators of Compromise

Unusual file types appearing in upload directories (e.g., .php, .phtml, .asp, .jsp files in image folders)
Unexpected web shell files in the application's document root or upload paths
HTTP requests to /register.php containing suspicious multipart form data with executable file extensions
Access logs showing requests to newly created files in upload directories with non-image extensions

Detection Strategies

Monitor file upload directories for non-image file types using file integrity monitoring (FIM) solutions
Implement web application firewall (WAF) rules to detect and block file uploads with dangerous extensions
Analyze HTTP POST requests to /register.php for multipart boundaries containing executable content types
Deploy SentinelOne endpoint protection to detect web shell deployment and execution attempts

Monitoring Recommendations

Enable detailed logging on the web server for all POST requests to /register.php
Configure alerts for new executable files created in web-accessible directories
Monitor for outbound connections from the web server process that may indicate post-exploitation activity
Review authentication logs for any suspicious registration attempts from unusual IP addresses or geographic locations

How to Mitigate CVE-2025-8255

Immediate Actions Required

Remove or disable the vulnerable /register.php functionality until a patch is available
Implement server-side file type validation that checks both file extensions and MIME types
Configure the web server to deny execution of scripts in upload directories
Apply strict file extension whitelisting to allow only legitimate image formats (.jpg, .png, .gif)
Deploy SentinelOne to monitor and protect against web shell uploads and execution

Patch Information

No official vendor patch has been released for this vulnerability at the time of publication. Organizations should monitor the Code Projects Security Resources for updates. Given the critical nature of this vulnerability and its public disclosure, immediate application of the workarounds below is strongly recommended.

Workarounds

Disable the file upload functionality in /register.php by commenting out or removing the relevant code
Implement .htaccess rules to prevent PHP execution in upload directories: php_flag engine off
Use a web application firewall to block requests containing potentially malicious file uploads
Move uploaded files outside the web root and serve them through a separate handler that validates file content
Implement content-type validation by reading file headers rather than relying on user-supplied data

bash

# Apache configuration to disable PHP execution in upload directory
<Directory "/var/www/html/uploads">
    php_flag engine off
    Options -ExecCGI
    RemoveHandler .php .phtml .php3 .php4 .php5 .phps
    AddType text/plain .php .phtml .php3 .php4 .php5 .phps
</Directory>