CVE-2025-5591
📋 TL;DR
Kentico Xperience 13 contains a stored cross-site scripting vulnerability in a form component that allows attackers to inject malicious scripts. When exploited, this enables session hijacking where attackers can perform actions within the victim's security context. Organizations using Kentico Xperience 13 are affected.
💻 Affected Systems
- Kentico Xperience
📦 What is this software?
Xperience by Kentico
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover leading to data theft, privilege escalation, and unauthorized administrative actions within the application.
Likely Case
Session hijacking allowing attackers to perform actions as authenticated users, potentially accessing sensitive data and functionality.
If Mitigated
Limited impact with proper input validation and output encoding, potentially only affecting non-critical functionality.
🎯 Exploit Status
Exploitation requires ability to submit malicious input through vulnerable form components.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Kentico Xperience 13 security updates
Vendor Advisory: https://www.themissinglink.com.au/security-advisories/cve-2025-5591
Restart Required: Yes
Instructions:
1. Check Kentico Xperience documentation for security updates. 2. Apply the latest security patch for version 13. 3. Restart the application services. 4. Verify the fix is applied.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement server-side input validation and output encoding for all form fields
Content Security Policy
allImplement strict CSP headers to mitigate XSS impact
🧯 If You Can't Patch
- Disable or restrict access to vulnerable form components
- Implement web application firewall rules to block XSS payloads
🔍 How to Verify
Check if Vulnerable:
Test form components for XSS vulnerability by submitting script payloads and checking if they executeCheck Version:
Check Kentico Xperience administration interface for version informationVerify Fix Applied:
Verify that script payloads submitted through forms are properly sanitized and do not execute📡 Detection & Monitoring
Log Indicators:
- Unusual form submissions with script tags or JavaScript code
- Multiple failed login attempts from same session
Network Indicators:
- HTTP requests containing script payloads in form parameters
SIEM Query:
source="web_logs" AND (form_data CONTAINS "<script>" OR form_data CONTAINS "javascript:")