CVE-2019-25301 Overview
CVE-2019-25301 is a persistent cross-site scripting (XSS) vulnerability affecting Millhouse-Project version 1.414. The vulnerability exists in the comment submission functionality, specifically within the add_comment_sql.php file. Attackers can exploit this flaw by injecting malicious JavaScript code through the content parameter when posting comments. Once stored, these malicious scripts execute in the browsers of any users who view the affected comments, enabling session hijacking, credential theft, and other client-side attacks.
Critical Impact
Attackers can execute arbitrary JavaScript in victim browsers, potentially stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of authenticated users.
Affected Products
- Millhouse-Project version 1.414
Discovery Timeline
- 2026-02-06 - CVE CVE-2019-25301 published to NVD
- 2026-02-06 - Last updated in NVD database
Technical Details for CVE-2019-25301
Vulnerability Analysis
This persistent XSS vulnerability (CWE-79) stems from inadequate input sanitization in the comment submission mechanism of Millhouse-Project. When users submit comments through add_comment_sql.php, the application fails to properly validate, sanitize, or encode the content parameter before storing it in the database. Subsequently, when these comments are rendered on the page, the malicious payload executes in the context of the viewing user's browser session.
Persistent (stored) XSS vulnerabilities are particularly dangerous compared to reflected XSS because the malicious payload is stored server-side and automatically delivered to all users who access the affected content, requiring no additional attacker interaction after the initial injection.
Root Cause
The root cause is insufficient input validation and output encoding in the comment handling workflow. The add_comment_sql.php script directly accepts and stores user-supplied content without sanitizing HTML or JavaScript code. When comments are displayed, the application fails to apply proper output encoding, allowing stored scripts to execute in visitors' browsers.
Attack Vector
The attack is network-based and requires low privileges (authenticated comment submission). An attacker submits a comment containing embedded JavaScript through the content parameter of add_comment_sql.php. The malicious script is stored in the application's database. When other users view the page containing the comment, the script executes in their browser context, potentially allowing the attacker to steal session tokens, perform actions as the victim, or redirect users to phishing pages.
The vulnerability requires some user interaction as victims must navigate to a page displaying the malicious comment. Technical details and proof-of-concept information are available through the Exploit-DB #47583 reference.
Detection Methods for CVE-2019-25301
Indicators of Compromise
- Presence of HTML tags or JavaScript code within stored comment content in the database
- Unexpected <script> tags, event handlers (e.g., onerror, onload), or encoded payloads in comment fields
- User reports of unexpected browser behavior, pop-ups, or redirects when viewing comments
- Web application firewall (WAF) logs showing XSS pattern matches in POST requests to add_comment_sql.php
Detection Strategies
- Implement web application firewall rules to detect and block XSS patterns in the content parameter
- Deploy browser-based Content Security Policy (CSP) headers to prevent inline script execution
- Monitor server logs for suspicious POST requests to add_comment_sql.php containing script tags or encoded JavaScript
- Perform regular database audits to identify stored content containing potential XSS payloads
Monitoring Recommendations
- Enable detailed logging for all comment submission endpoints
- Configure alerting for WAF rule triggers related to XSS attack patterns
- Monitor for unusual session activity that may indicate session hijacking following XSS exploitation
- Review Content Security Policy violation reports if CSP is deployed
How to Mitigate CVE-2019-25301
Immediate Actions Required
- Audit existing comments in the database and remove or sanitize any containing script tags or suspicious HTML
- Implement server-side input validation to reject or sanitize comments containing HTML or JavaScript
- Apply output encoding (HTML entity encoding) when rendering user-submitted content
- Deploy Content Security Policy headers to mitigate the impact of any XSS vulnerabilities
Patch Information
No official vendor patch has been identified in the available references. Organizations using Millhouse-Project should review the GitHub Millhouse Project Repository for any updates or patches. The VulnCheck Advisory for Millhouse Project provides additional context on this vulnerability.
Workarounds
- Implement strict input validation on the content parameter to strip or encode HTML tags and JavaScript
- Apply HTML entity encoding to all user-submitted content before rendering in the browser
- Deploy Content Security Policy headers with script-src 'self' to prevent inline script execution
- Consider using a web application firewall to filter malicious input patterns before they reach the application
# Example Apache configuration to add Content Security Policy header
# Add to .htaccess or virtual host configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
