CVE-2015-20113: RealtyScript CSRF Vulnerability

CVE-2015-20113 Overview

CVE-2015-20113 affects Next Click Ventures RealtyScript 4.0.2, a real estate listing and property management web application. The vulnerability encompasses both Cross-Site Request Forgery (CSRF) and persistent Cross-Site Scripting (XSS) flaws that enable attackers to perform unauthorized administrative actions and inject malicious scripts into the application.

Attackers can craft malicious web pages that execute unauthorized actions when authenticated users visit them. Additionally, the persistent XSS component allows injection of scripts that execute within the application context, potentially compromising all users who access affected pages.

Critical Impact

Successful exploitation allows attackers to hijack administrative sessions, modify application data, steal user credentials, and execute arbitrary JavaScript in the context of authenticated users.

Affected Products

• Next Click Ventures RealtyScript version 4.0.2
• RealtyScript installations without CSRF token protection
• RealtyScript deployments with insufficient input sanitization

Discovery Timeline

• March 16, 2026 - CVE-2015-20113 published to NVD
• March 19, 2026 - Last updated in NVD database

Technical Details for CVE-2015-20113

Vulnerability Analysis

This vulnerability combines two distinct attack vectors that together present a significant risk to RealtyScript installations. The CSRF component (CWE-352) results from the application failing to validate the origin of state-changing requests, allowing attackers to trick authenticated administrators into executing unintended actions.

The persistent XSS component allows malicious scripts to be stored within the application database and subsequently rendered to other users without proper sanitization. When combined, these vulnerabilities enable sophisticated attack chains where CSRF can be used to inject persistent XSS payloads that then affect all application users.

The network-based attack vector requires no special privileges or authentication to initiate, though the impact depends on victim interaction with malicious content. The absence of proper anti-CSRF tokens and inadequate output encoding are the underlying technical deficiencies.

Root Cause

The vulnerability stems from two fundamental security oversights in RealtyScript 4.0.2. First, the application does not implement CSRF tokens or verify request origins for sensitive operations, allowing any website to submit forms on behalf of authenticated users. Second, user-supplied input is stored and later rendered without proper HTML entity encoding or content security policies, enabling persistent script injection.

Attack Vector

The attack is network-based and requires user interaction. An attacker creates a malicious webpage containing hidden forms or JavaScript that automatically submits requests to the vulnerable RealtyScript installation. When an authenticated administrator visits this page, the forged requests execute with the victim's session privileges.

For the XSS component, attackers can inject JavaScript payloads through input fields that are later displayed to other users. These payloads persist in the application database and execute whenever the affected content is viewed, enabling session hijacking, keylogging, and credential theft.

The vulnerability details and exploitation techniques are documented in the Zero Science Vulnerability Advisory ZSL-2015-5269 and Exploit-DB #38496.

Detection Methods for CVE-2015-20113

Indicators of Compromise

• Unexpected administrative changes in RealtyScript without corresponding legitimate activity
• Presence of <script> tags or encoded JavaScript in database fields storing user content
• Anomalous form submissions originating from external referrers in web server logs
• User reports of unexpected browser behavior when accessing property listings

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect CSRF attack patterns and XSS payloads
• Monitor HTTP referrer headers for requests to administrative endpoints from external domains
• Deploy Content Security Policy (CSP) headers to detect and report inline script execution attempts
• Scan database fields periodically for HTML/JavaScript content that should not be present

Monitoring Recommendations

• Enable detailed access logging on web servers hosting RealtyScript installations
• Configure alerts for form submissions to administrative endpoints without valid CSRF tokens
• Monitor for anomalous session activity patterns that may indicate session hijacking
• Implement browser-side reporting for CSP violations to detect XSS exploitation attempts

How to Mitigate CVE-2015-20113

Immediate Actions Required

• Restrict administrative access to RealtyScript by IP address or VPN until patching is complete
• Implement a Web Application Firewall with rules blocking known CSRF and XSS attack patterns
• Audit existing database content for injected scripts and sanitize any malicious entries
• Configure Content Security Policy headers to prevent inline script execution

Patch Information

No vendor patch information is currently available in the advisory data. Organizations should contact Next Click Ventures directly for guidance on security updates. Review the VulnCheck Advisory for the latest remediation guidance.

Workarounds

• Implement server-side CSRF token validation using a reverse proxy or application wrapper
• Add output encoding for all user-controlled content displayed in HTML contexts
• Deploy strict Content Security Policy headers: Content-Security-Policy: script-src 'self'
• Limit administrative session duration and require re-authentication for sensitive operations
• Consider migrating to an actively maintained real estate platform if vendor support is unavailable

# Example Apache configuration for basic CSRF protection via referrer validation
# Add to .htaccess or Apache configuration for RealtyScript admin directory

<Directory "/var/www/realtyscript/admin">
    SetEnvIf Referer "^https?://yourdomain\.com" valid_referer
    <RequireAll>
        Require all granted
        Require env valid_referer
    </RequireAll>
</Directory>

# Add security headers
<IfModule mod_headers.c>
    Header always set Content-Security-Policy "script-src 'self'; object-src 'none'"
    Header always set X-Content-Type-Options "nosniff"
    Header always set X-XSS-Protection "1; mode=block"
</IfModule>