CVE-2025-15415: wangmarket Unrestricted Upload RCE Flaw

CVE-2025-15415 Overview

A vulnerability has been identified in xnx3 wangmarket versions up to 6.4. The vulnerability affects the uploadImage function within the /sits/uploadImage.do endpoint of the XML File Handler component. Due to improper access control, an attacker can exploit this flaw to perform unrestricted file uploads, which may lead to stored Cross-Site Scripting (XSS) attacks. Remote exploitation is possible, and a public exploit has been disclosed.

Critical Impact

This unrestricted file upload vulnerability allows remote attackers to upload arbitrary files to the server, potentially leading to stored XSS attacks that can compromise user sessions, steal credentials, or deliver malicious content to application users.

Affected Products

• xnx3 wangmarket up to version 6.4
• XML File Handler component (/sits/uploadImage.do)
• uploadImage function handling image argument processing

Discovery Timeline

• 2026-01-01 - CVE-2025-15415 published to NVD
• 2026-01-02 - Last updated in NVD database

Technical Details for CVE-2025-15415

Vulnerability Analysis

This vulnerability stems from improper access control (CWE-284) in the file upload functionality of the wangmarket content management system. The uploadImage function fails to properly validate and restrict the types of files that can be uploaded through the image parameter. This lack of proper file type validation creates an attack surface where malicious content can be uploaded and subsequently served to other users.

The vulnerability was disclosed publicly, and the vendor was contacted about the issue but did not respond. This lack of vendor response increases the risk for organizations running affected versions, as no official patch is currently available.

Root Cause

The root cause is improper access control (CWE-284) in the file upload handling mechanism. The uploadImage function does not implement adequate validation of uploaded file content or file types, allowing attackers to bypass intended restrictions. This represents a failure to enforce least privilege principles and proper input validation on user-supplied data.

Attack Vector

The attack is network-accessible and can be exploited remotely. An attacker with elevated privileges (PR:H) can target the /sits/uploadImage.do endpoint and manipulate the image argument to upload malicious files. The uploaded content can then be leveraged for stored XSS attacks, where the malicious payload executes in the context of other users' browsers when they access the uploaded content.

The attack flow involves:

1. Attacker authenticates to the wangmarket application with elevated privileges
2. Crafts a malicious upload request targeting /sits/uploadImage.do
3. Manipulates the image parameter to include malicious content (e.g., SVG with embedded JavaScript)
4. Uploaded file is stored on the server without proper sanitization
5. When other users access the uploaded content, the malicious script executes in their browser context

For technical details and proof-of-concept information, refer to the GitHub PoC Repository.

Detection Methods for CVE-2025-15415

Indicators of Compromise

• Unusual file uploads to the /sits/uploadImage.do endpoint containing non-image content types
• SVG files or other XML-based images containing embedded JavaScript or event handlers
• Server logs showing multiple upload requests from a single source with varying file extensions
• User reports of unexpected script execution or browser behavior when viewing uploaded images

Detection Strategies

• Implement web application firewall (WAF) rules to inspect file upload requests for embedded scripts or malicious content
• Monitor HTTP POST requests to /sits/uploadImage.do for suspicious payloads or unusual file signatures
• Deploy file integrity monitoring on upload directories to detect unexpected file types
• Enable detailed logging for the XML File Handler component and review for anomalous patterns

Monitoring Recommendations

• Configure SIEM alerts for high-volume upload activity to the affected endpoint
• Establish baseline upload patterns and alert on deviations in file size, type, or frequency
• Monitor for client-side XSS indicators such as unexpected cookie access or DOM manipulation attempts
• Review server access logs for requests to uploaded files from multiple distinct IP addresses

How to Mitigate CVE-2025-15415

Immediate Actions Required

• Restrict access to the /sits/uploadImage.do endpoint to only trusted administrators
• Implement strict file type validation on all uploads, checking both file extension and MIME type
• Consider temporarily disabling the file upload functionality until proper controls can be implemented
• Audit existing uploaded files for potentially malicious content

Patch Information

No official patch is currently available from the vendor. The vendor was contacted about this disclosure but did not respond. Organizations should implement the workarounds below and monitor for future vendor updates. Additional details are available at VulDB #339336.

Workarounds

• Implement server-side content validation that checks actual file content, not just headers or extensions
• Configure Content Security Policy (CSP) headers to mitigate the impact of stored XSS attacks
• Serve uploaded files from a separate domain or with Content-Disposition: attachment headers to prevent script execution
• Use a web application firewall to filter malicious upload attempts targeting the affected endpoint

# Example: Apache configuration to restrict file uploads and add security headers
# Add to .htaccess or virtual host configuration

# Block direct access to upload handler for non-admin IPs
<Location /sits/uploadImage.do>
    Require ip 192.168.1.0/24
</Location>

# Add Content Security Policy header
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; img-src 'self' data:;"

# Force download for uploaded files in upload directory
<Directory /var/www/html/uploads>
    Header set Content-Disposition "attachment"
    Header set X-Content-Type-Options "nosniff"
</Directory>