CVE-2025-20204
📋 TL;DR
An authenticated cross-site scripting (XSS) vulnerability in Cisco ISE's web management interface allows attackers with administrative credentials to inject malicious scripts. This could lead to session hijacking, data theft, or unauthorized actions within the management interface. Only Cisco ISE systems with vulnerable versions are affected.
💻 Affected Systems
- Cisco Identity Services Engine (ISE)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains full administrative control of ISE, compromises all network authentication/authorization, steals sensitive credentials and configuration data, and pivots to other network systems.
Likely Case
Attacker steals session cookies or credentials of legitimate administrators, performs unauthorized configuration changes, or extracts sensitive information from the management interface.
If Mitigated
Limited impact due to strong access controls, network segmentation, and monitoring; attacker may achieve limited data exposure but cannot pivot to critical systems.
🎯 Exploit Status
Exploitation requires valid admin credentials and ability to inject scripts into specific web pages.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Cisco advisory for specific patched versions
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-xss-42tgsdMG
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions. 2. Download and apply the recommended patch/upgrade. 3. Restart ISE services or appliance as required. 4. Verify patch application through version check.
🔧 Temporary Workarounds
Restrict Administrative Access
allLimit access to ISE management interface to trusted IP addresses/networks only
Configure firewall/ACL rules to restrict access to ISE management IP:443
Implement Web Application Firewall
allDeploy WAF with XSS protection rules in front of ISE management interface
🧯 If You Can't Patch
- Implement strict network segmentation to isolate ISE management interface
- Enforce strong authentication and session management controls
🔍 How to Verify
Check if Vulnerable:
Check ISE version against affected versions in Cisco advisoryCheck Version:
show version (from ISE CLI) or check Admin > System > About in web interfaceVerify Fix Applied:
Verify ISE version matches patched version from advisory and test interface functionality📡 Detection & Monitoring
Log Indicators:
- Unusual administrative login patterns
- Unexpected configuration changes
- Web interface error logs showing script injection attempts
Network Indicators:
- Unusual HTTP POST requests to ISE management interface with script tags
- Traffic from unauthorized sources to management interface
SIEM Query:
source="ise_logs" AND (http_method="POST" AND (uri="*" AND content="*<script>*"))