CVE-2025-13574: Online Bidding System RCE Vulnerability

CVE-2025-13574 Overview

CVE-2025-13574 is an unrestricted file upload vulnerability [CWE-434] in code-projects Online Bidding System 1.0. The flaw resides in the categoryadd function of /administrator/addcategory.php. Attackers can manipulate the catimage argument to upload arbitrary files to the application. The issue also reflects an improper access control weakness [CWE-284]. Remote exploitation is possible, and the exploit details have been published. The vulnerability requires high privileges to exploit, limiting its practical impact to authenticated administrative contexts. Successful exploitation can lead to malicious file placement within the web server directory structure.

Critical Impact
Authenticated attackers with administrative access can upload arbitrary files through the category creation feature, potentially leading to web shell deployment and follow-on compromise of the hosting environment.

Affected Products

code-projects Online Bidding System 1.0
Fabian Online Bidding System (fabian:online_bidding_system:1.0)
/administrator/addcategory.php component

Discovery Timeline

2025-11-24 - CVE-2025-13574 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2025-13574

Vulnerability Analysis

The vulnerability resides in the administrator-side category management workflow of the Online Bidding System. The categoryadd function in /administrator/addcategory.php accepts a file via the catimage parameter without enforcing restrictions on file type, extension, or content. As a result, an attacker with administrator privileges can submit a file masquerading as a category image but containing server-executable code such as PHP. Once written to a web-accessible directory, the uploaded file can be requested directly to trigger code execution within the web server context. The flaw is categorized under both CWE-434 (Unrestricted Upload of File with Dangerous Type) and CWE-284 (Improper Access Control). Public documentation of the exploit increases the likelihood of opportunistic use against exposed instances.

Root Cause

The root cause is missing server-side validation in the categoryadd handler. The application trusts the client-supplied file submitted through the catimage field and writes it to disk without checking the MIME type, extension allow-list, magic bytes, or executable disposition. There is no separation between user-uploaded content and the executable web root.

Attack Vector

An authenticated administrator submits a crafted multipart form POST to /administrator/addcategory.php, replacing the expected image data in catimage with a PHP payload bearing an executable extension. The server stores the file in a public path, and the attacker subsequently requests the file over HTTP to invoke the payload. Public technical details are documented in the GitHub CVE writeup and VulDB entry #333338.

Detection Methods for CVE-2025-13574

Indicators of Compromise

Unexpected files with executable extensions (.php, .phtml, .phar) stored in directories used for category images.
Web server access log entries showing POST requests to /administrator/addcategory.php followed by GET requests to newly created files under upload paths.
New or modified administrator sessions immediately preceding file write events in category-related directories.

Detection Strategies

Monitor file integrity in administrator upload directories and alert on creation of non-image MIME types.
Correlate authentication events for the administrator role with subsequent file write operations in the web root.
Inspect HTTP request bodies sent to addcategory.php for content disposition headers carrying scripting extensions in the catimage field.

Monitoring Recommendations

Enable verbose web server logging for the /administrator/ path, including request methods, file names, and response codes.
Forward web and host logs to a centralized analytics platform to detect upload-then-execute sequences against the same file path.
Track outbound network connections from the web server process, which may indicate a web shell calling back to attacker infrastructure.

How to Mitigate CVE-2025-13574

Immediate Actions Required

Restrict network exposure of the /administrator/ interface to trusted management IP ranges until a vendor patch is verified.
Rotate administrator credentials and review existing administrator accounts for unauthorized additions.
Audit category image directories for unexpected files and remove any non-image content found.

Patch Information

No vendor advisory or official patch is referenced in the available CVE data. Operators should monitor code-projects.org and the VulDB record for updates. Until a fix is published, apply the workarounds below.

Workarounds

Add server-side validation in addcategory.php to enforce an allow-list of image extensions and verify file magic bytes for catimage.
Configure the web server to disable script execution within upload directories using directives such as php_flag engine off or equivalent handler restrictions.
Store uploaded files outside the web root and serve them through a controlled handler that sets a non-executable content type.
Place the application behind a web application firewall with rules that block multipart uploads containing PHP tags or executable extensions to administrator endpoints.

bash

# Configuration example: disable PHP execution in upload directory (Apache)
<Directory "/var/www/online_bidding_system/uploads">
    php_flag engine off
    AddType text/plain .php .phtml .phar .php5
    Options -ExecCGI
</Directory>