CVE-2025-59539
📋 TL;DR
This is a stored cross-site scripting (XSS) vulnerability in DNN CMS where authenticated users can inject malicious JavaScript into the Biography field. The injected code executes in victims' browsers when they view the attacker's profile, potentially affecting all users including administrators. DNN versions before 10.1.0 are vulnerable.
💻 Affected Systems
- DNN (DotNetNuke) CMS
📦 What is this software?
Dotnetnuke by Dnnsoftware
Dotnetnuke by Dnnsoftware
⚠️ Risk & Real-World Impact
Worst Case
An attacker could steal administrator session cookies, perform actions as administrators, deface the website, or redirect users to malicious sites.
Likely Case
Attackers steal user session cookies, perform limited actions as compromised users, or deface user profiles.
If Mitigated
With proper input validation and output encoding, the JavaScript would be rendered harmless as text.
🎯 Exploit Status
Requires authenticated user access. Exploitation is straightforward once an account is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.0
Vendor Advisory: https://github.com/dnnsoftware/Dnn.Platform/security/advisories/GHSA-7rcc-q6rq-jpcm
Restart Required: No
Instructions:
1. Backup your DNN installation and database. 2. Download DNN Platform 10.1.0 or later from the official repository. 3. Follow the standard DNN upgrade procedure. 4. Verify the upgrade completed successfully.
🔧 Temporary Workarounds
Disable Biography Field
allRemove or disable the Biography field from user profiles to prevent injection.
Implement Input Validation
allAdd server-side validation to sanitize Biography field input before storage.
🧯 If You Can't Patch
- Implement a Web Application Firewall (WAF) with XSS protection rules
- Apply Content Security Policy (CSP) headers to restrict script execution
🔍 How to Verify
Check if Vulnerable:
Check DNN version in Host Settings > Basic Settings. If version is below 10.1.0, the system is vulnerable.Check Version:
Check Host Settings in DNN admin panel or examine web.config file for version information.Verify Fix Applied:
After upgrading to 10.1.0 or later, test if JavaScript in Biography field is properly sanitized and doesn't execute.📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript patterns in user profile updates
- Multiple failed XSS attempts in logs
Network Indicators:
- Unexpected script tags in profile page responses
- Suspicious outbound connections from profile pages
SIEM Query:
source="dnn_logs" AND ("Biography" OR "profile") AND ("script" OR "javascript" OR "onclick")