CVE-2015-20116 Overview
CVE-2015-20116 is a stored Cross-Site Scripting (XSS) vulnerability in Next Click Ventures RealtyScript version 4.0.2. The application fails to properly sanitize CSV file uploads, allowing attackers to inject malicious scripts through filename parameters in multipart form data. Attackers can upload files with XSS payloads in the filename field to execute arbitrary JavaScript in users' browsers when the file is processed or displayed.
Critical Impact
This stored XSS vulnerability enables attackers to execute arbitrary JavaScript code in authenticated users' browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of victims.
Affected Products
- Next Click Ventures RealtyScript 4.0.2
- nextclickventures realtyscript (cpe:2.3:a:nextclickventures:realtyscript:4.0.2:::::::*)
Discovery Timeline
- 2026-03-16 - CVE CVE-2015-20116 published to NVD
- 2026-03-19 - Last updated in NVD database
Technical Details for CVE-2015-20116
Vulnerability Analysis
This vulnerability exists in the CSV file upload functionality of RealtyScript. The application accepts multipart form data for file uploads but does not adequately sanitize the filename parameter before storing or rendering it within the application's interface. When administrators or users view uploaded files, the malicious filename containing JavaScript code is rendered without proper encoding, causing the browser to execute the embedded script.
The attack is network-based and requires user interaction—specifically, a victim must view the page where the malicious filename is displayed. As a stored XSS vulnerability, the payload persists within the application, affecting any user who subsequently views the affected page.
Root Cause
The root cause is improper input validation (CWE-79) in the file upload handler. The application fails to sanitize or encode special characters in the filename field of uploaded CSV files. When these filenames are later displayed in the web interface, they are rendered as HTML without proper output encoding, enabling script injection.
Attack Vector
The attack vector is network-based, requiring an attacker to craft a malicious multipart form data request containing a specially crafted filename with embedded JavaScript. The attacker uploads a CSV file where the filename field contains an XSS payload such as a script tag or event handler. When the application stores and later displays this filename (for example, in a file listing, upload confirmation, or administrative interface), the malicious script executes in the context of the victim's browser session.
The attack requires the attacker to have upload permissions and relies on a victim viewing the page where the filename is displayed. Once triggered, the attacker can steal session cookies, perform actions as the authenticated user, or redirect users to malicious sites.
Detection Methods for CVE-2015-20116
Indicators of Compromise
- Unusual filenames in CSV upload directories containing script tags, event handlers (onerror, onload), or JavaScript pseudo-protocol URIs
- Web server logs showing multipart form data uploads with encoded script characters in filename parameters
- User reports of unexpected browser behavior when viewing file listings in RealtyScript
Detection Strategies
- Implement web application firewall (WAF) rules to detect XSS patterns in filename parameters of multipart form data
- Monitor application logs for file uploads containing suspicious characters such as <, >, script, or javascript: in filename fields
- Deploy endpoint detection solutions to identify malicious script execution originating from the RealtyScript application
Monitoring Recommendations
- Enable detailed logging for all file upload operations including complete filename parameters
- Configure alerting for filenames containing HTML special characters or common XSS payload signatures
- Regularly audit uploaded files and their metadata for signs of injection attempts
How to Mitigate CVE-2015-20116
Immediate Actions Required
- Restrict file upload functionality to trusted users only until a patch is available
- Implement server-side filename sanitization to strip or encode special characters before storage
- Apply Content Security Policy (CSP) headers to mitigate the impact of successful XSS attacks
- Review and audit existing uploaded files for malicious filename patterns
Patch Information
No vendor patch information is available in the current CVE data. Organizations using RealtyScript 4.0.2 should contact Next Click Ventures for security updates or consider implementing compensating controls. For technical details about this vulnerability, refer to the Zero Science Vulnerability Advisory ZSL-2015-5269 or the Vulncheck Security Advisory.
Workarounds
- Implement input validation on the server side to reject or sanitize filenames containing potentially dangerous characters such as <, >, ", ', and &
- Apply HTML entity encoding to all user-supplied data, including filenames, before rendering in the web interface
- Use a web application firewall to block requests containing XSS patterns in file upload parameters
- Consider disabling or restricting the CSV upload feature until proper sanitization is implemented
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
