CVE-2025-20353
📋 TL;DR
An unauthenticated cross-site scripting (XSS) vulnerability in Cisco Catalyst Center's web management interface allows remote attackers to execute malicious scripts in users' browsers. This affects administrators and users accessing the web interface of vulnerable Cisco Catalyst Center deployments. Attackers can exploit this by tricking users into clicking specially crafted links.
💻 Affected Systems
- Cisco Catalyst Center
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of administrator accounts leading to full network control, data exfiltration, and lateral movement across managed infrastructure.
Likely Case
Session hijacking, credential theft, and unauthorized configuration changes to network devices managed by Catalyst Center.
If Mitigated
Limited to temporary session disruption or minor information disclosure if proper input validation and output encoding are implemented.
🎯 Exploit Status
Exploitation requires social engineering to trick users into clicking malicious links
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Cisco advisory for specific fixed versions
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-dnac-xss-weXtVZ59
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions
2. Download and apply recommended software update from Cisco
3. Restart Catalyst Center services as required
4. Verify interface functionality post-update
🔧 Temporary Workarounds
Input Validation Enhancement
allImplement additional input validation and output encoding in web interface
Content Security Policy
allDeploy strict Content Security Policy headers to restrict script execution
🧯 If You Can't Patch
- Restrict web interface access to trusted networks only
- Implement web application firewall with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Check Catalyst Center version against Cisco advisory; test with safe XSS payload in input fieldsCheck Version:
Check via Catalyst Center web interface or CLI: show versionVerify Fix Applied:
Verify installed version matches patched version from advisory; test XSS vectors no longer execute📡 Detection & Monitoring
Log Indicators:
- Unusual JavaScript execution in web interface logs
- Suspicious URL parameters containing script tags
- Multiple failed authentication attempts following suspicious links
Network Indicators:
- HTTP requests with encoded script payloads in parameters
- Traffic to Catalyst Center interface from unexpected sources
SIEM Query:
source="catalyst_center" AND (http_uri="*<script*" OR http_uri="*javascript:*" OR http_uri="*onerror=*")