CVE-2025-48377
📋 TL;DR
This Cross-Site Scripting (XSS) vulnerability in DNN CMS allows attackers to inject malicious scripts via specially crafted URLs when using certain module actions. The vulnerability affects all DNN installations prior to version 9.13.9, potentially compromising user sessions and data.
💻 Affected Systems
- DNN Platform (formerly DotNetNuke)
📦 What is this software?
Dotnetnuke by Dnnsoftware
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users, potentially leading to full account compromise.
Likely Case
Session hijacking, credential theft, or defacement of website content through injected scripts.
If Mitigated
Limited impact if proper Content Security Policy (CSP) headers are implemented and user input validation is enforced.
🎯 Exploit Status
XSS vulnerabilities are commonly weaponized; the advisory provides technical details but no public exploit code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.13.9
Vendor Advisory: https://github.com/dnnsoftware/Dnn.Platform/security/advisories/GHSA-79m3-rvx2-3qq9
Restart Required: Yes
Instructions:
1. Backup your DNN installation and database. 2. Download DNN Platform version 9.13.9 or later. 3. Follow the official DNN upgrade guide. 4. Restart the application pool/IIS. 5. Verify the upgrade completed successfully.
🔧 Temporary Workarounds
Implement Content Security Policy
windowsAdd CSP headers to restrict script execution sources and mitigate XSS impact.
Add to web.config: <add name="Content-Security-Policy" value="default-src 'self'; script-src 'self'" />
Input Validation Filtering
allImplement additional input validation for URL parameters in custom modules.
Implement Microsoft AntiXSS library or similar input sanitization in module code.
🧯 If You Can't Patch
- Implement Web Application Firewall (WAF) rules to block XSS payloads in URLs.
- Disable or restrict access to vulnerable modules if identified.
🔍 How to Verify
Check if Vulnerable:
Check DNN version in Host Settings > Basic Settings; if version is below 9.13.9, system is vulnerable.Check Version:
Check Host Settings in DNN admin panel or examine web.config for version information.Verify Fix Applied:
After upgrade, confirm version shows 9.13.9 or higher in Host Settings and test URL parameter handling.📡 Detection & Monitoring
Log Indicators:
- Unusual long URL parameters containing script tags or JavaScript in IIS logs
- Multiple 400/500 errors from module actions with suspicious parameters
Network Indicators:
- HTTP requests with encoded script payloads in query strings
- Unexpected redirects to external domains
SIEM Query:
source="IIS" AND (url="*<script*" OR url="*javascript:*" OR status_code=400 OR status_code=500)