CVE-2015-20118: RealtyScript Stored XSS Vulnerability

CVE-2015-20118 Overview

CVE-2015-20118 is a stored cross-site scripting (XSS) vulnerability affecting Next Click Ventures RealtyScript 4.0.2, a real estate listing software platform. The vulnerability exists in the location_name parameter within the admin locations interface, allowing authenticated attackers to inject malicious JavaScript payloads that execute in administrator browsers when viewing affected pages.

This stored XSS vulnerability enables attackers with low-privilege access to submit crafted POST requests to the locations.php endpoint containing JavaScript code in the location_name field. Once stored, this malicious payload executes whenever an administrator accesses the locations management interface, potentially leading to session hijacking, administrative credential theft, or further compromise of the web application.

Critical Impact

Authenticated attackers can persistently inject malicious scripts that execute in administrator contexts, potentially enabling full administrative account takeover and unauthorized system access.

Affected Products

• Next Click Ventures RealtyScript version 4.0.2
• Nextclickventures RealtyScript (unpatched installations)

Discovery Timeline

• 2026-03-16 - CVE-2015-20118 published to NVD
• 2026-03-19 - Last updated in NVD database

Technical Details for CVE-2015-20118

Vulnerability Analysis

This stored cross-site scripting vulnerability (CWE-79) stems from insufficient input validation and output encoding in the RealtyScript administrative interface. The application fails to properly sanitize user-supplied input in the location_name parameter before storing it in the database and subsequently rendering it in the admin panel.

When an attacker with authenticated access submits a location entry containing JavaScript code, the malicious payload is stored server-side without sanitization. Subsequently, when administrators view the locations list through the admin interface, the stored payload executes within their browser session with full access to the administrative context.

The network-based attack vector requires user interaction (administrator must view the affected page), but the persistent nature of the stored XSS means the payload remains active until manually removed, affecting multiple administrator sessions over time.

Root Cause

The root cause of CVE-2015-20118 is improper input validation and missing output encoding in the RealtyScript location management functionality. Specifically:

1. The locations.php endpoint accepts POST parameters without adequate sanitization
2. The location_name field allows arbitrary HTML and JavaScript content to be stored
3. When rendering location data in the admin interface, the application fails to apply proper output encoding, allowing stored scripts to execute in the browser context

This represents a classic stored XSS pattern where user input flows from an untrusted source through persistent storage to a vulnerable sink without proper encoding at any stage.

Attack Vector

The attack is executed through the following mechanism:

1. An attacker with authenticated access to the RealtyScript admin panel navigates to the locations management interface
2. The attacker submits a POST request to locations.php with a malicious JavaScript payload embedded in the location_name parameter
3. The application stores this unvalidated input in the database
4. When any administrator subsequently views the locations list, the malicious script executes in their browser context
5. The attacker can leverage this execution to steal session cookies, capture credentials, or perform administrative actions on behalf of the victim

Technical details and proof-of-concept information are available in the Zero Science Vulnerability Advisory ZSL-2015-5269 and the Exploit-DB entry #38496.

Detection Methods for CVE-2015-20118

Indicators of Compromise

• Presence of JavaScript tags or encoded script content within location name entries in the database
• Unusual <script>, onerror, onload, or event handler attributes stored in the locations table
• POST requests to locations.php containing encoded characters or suspicious JavaScript syntax
• Administrator session anomalies or unauthorized administrative actions following location list viewing

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payload patterns in POST request parameters
• Monitor HTTP POST requests to locations.php for common XSS indicators such as <script>, javascript:, and HTML event handlers
• Review database entries in location-related tables for stored HTML or JavaScript content that should not be present
• Enable application logging to capture all administrative interface access and parameter submissions

Monitoring Recommendations

• Configure real-time alerting for POST requests containing script tags or JavaScript event handlers targeting admin endpoints
• Implement Content Security Policy (CSP) headers to mitigate impact of successful XSS exploitation
• Establish baseline administrative user behavior and alert on anomalous session activity following location interface access
• Regularly audit stored data in location tables for injected malicious content

How to Mitigate CVE-2015-20118

Immediate Actions Required

• Upgrade RealtyScript to a patched version if available from the vendor
• Implement input validation to reject HTML and JavaScript content in the location_name parameter
• Apply output encoding (HTML entity encoding) when rendering location names in the admin interface
• Audit existing location database entries for malicious content and sanitize any discovered payloads
• Restrict admin panel access to trusted IP ranges where feasible

Patch Information

No vendor patch information is currently available in the CVE data. Organizations should contact Next Click Ventures directly for security update availability or consider implementing the workarounds below. Additional vulnerability details can be found in the VulnCheck Advisory on RealtyScript.

Workarounds

• Implement a Web Application Firewall (WAF) with XSS detection rules to filter malicious input before it reaches the application
• Deploy Content Security Policy headers (Content-Security-Policy: script-src 'self') to prevent inline script execution
• Apply server-side input validation to strip HTML tags and JavaScript from the location_name parameter
• Implement HTTPOnly and Secure flags on session cookies to reduce impact of potential session theft
• Consider restricting write access to the locations interface to only fully trusted administrators

# Example Apache configuration for CSP headers
# Add to .htaccess or Apache configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'"
Header set X-XSS-Protection "1; mode=block"
Header set X-Content-Type-Options "nosniff"