CVE-2026-4875: Hotel Reservation System RCE Vulnerability

CVE-2026-4875 Overview

CVE-2026-4875 is an unrestricted file upload vulnerability discovered in itsourcecode Free Hotel Reservation System 1.0. The vulnerability exists in an unknown function of the file /admin/mod_amenities/index.php?view=add, where manipulation of the image argument allows attackers to upload arbitrary files without proper validation. This flaw enables remote attackers to potentially upload malicious files to the target server, which could lead to code execution or other malicious activities.

Critical Impact
Remote attackers can exploit improper access control in the administrative image upload functionality to upload arbitrary files, potentially leading to remote code execution or complete system compromise.

Affected Products

itsourcecode Free Hotel Reservation System 1.0

Discovery Timeline

2026-03-26 - CVE-2026-4875 published to NVD
2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-4875

Vulnerability Analysis

This vulnerability stems from improper access control (CWE-284) in the administrative module for managing amenities. The affected endpoint /admin/mod_amenities/index.php?view=add processes image uploads without implementing sufficient security controls. When a file is submitted through the image parameter, the application fails to properly validate the file type, content, or extension before storing it on the server.

The vulnerability is exploitable over the network by attackers with high privileges (administrative access). While the individual impact on confidentiality, integrity, and availability is limited, the combination of these factors in a file upload context can enable more serious attack chains, particularly if the uploaded file can be executed by the web server.

Root Cause

The root cause of this vulnerability is improper access control and missing input validation on the file upload functionality. The application does not implement proper checks to verify that uploaded files are legitimate images. This includes the absence of:

File extension validation against an allowlist
MIME type verification
Content-based file type detection
File size restrictions
Randomization or sanitization of uploaded filenames

Attack Vector

The attack can be executed remotely over the network. An attacker with administrative credentials can navigate to the amenities management module and submit a malicious file through the image upload form. The exploit has been publicly disclosed, increasing the risk of exploitation.

The attack flow typically involves:

Authenticating to the administrative panel
Navigating to /admin/mod_amenities/index.php?view=add
Crafting a malicious file (e.g., a PHP web shell disguised as an image)
Uploading the file through the image parameter
Locating and accessing the uploaded file to trigger execution

Technical details and proof-of-concept information can be found in the GitHub Issue Discussion and VulDB #353558.

Detection Methods for CVE-2026-4875

Indicators of Compromise

Unusual file types appearing in the upload directories of the Hotel Reservation System
PHP, JSP, ASP, or other executable files in image upload directories
Web shell signatures or suspicious file names in the amenities module storage location
Unexpected outbound connections from the web server

Detection Strategies

Monitor file creation events in the web application's upload directories for non-image file extensions
Implement file integrity monitoring (FIM) on the application's upload directories
Deploy web application firewall (WAF) rules to inspect file upload requests for malicious content
Review web server access logs for requests to unusual files in upload directories

Monitoring Recommendations

Enable verbose logging for the administrative module and file upload operations
Configure alerts for new file creation events with executable extensions in web-accessible directories
Monitor for process execution originating from the web server's document root
Implement network-level monitoring for suspicious outbound traffic from the web server

How to Mitigate CVE-2026-4875

Immediate Actions Required

Restrict access to the administrative panel to trusted IP addresses only
Implement authentication hardening and multi-factor authentication for admin accounts
Consider disabling the amenities image upload functionality until a patch is available
Review and remove any suspicious files from the upload directories

Patch Information

No official patch has been released by the vendor at this time. Organizations using itsourcecode Free Hotel Reservation System should monitor the IT Source Code website for security updates. Given the open-source nature of the project, administrators may need to implement their own fixes or consider alternative solutions.

Workarounds

Implement server-side file type validation that checks both file extension and MIME type against an allowlist of permitted image formats
Configure the web server to prevent execution of uploaded files by disabling script execution in upload directories
Use a separate storage location outside the web root for uploaded files
Implement Content-Security-Policy headers to prevent execution of uploaded content
Consider using a reverse proxy with file scanning capabilities to inspect uploads before they reach the application

bash

# Apache configuration to prevent script execution in upload directories
<Directory "/var/www/html/uploads">
    # Disable PHP execution
    php_admin_flag engine off
    
    # Disable script execution
    Options -ExecCGI
    
    # Only allow specific file types
    <FilesMatch "\.(?!(jpg|jpeg|png|gif)$)[^.]*$">
        Require all denied
    </FilesMatch>
</Directory>