CVE-2026-20123
📋 TL;DR
An open redirect vulnerability in Cisco EPNM and Prime Infrastructure web interfaces allows attackers to redirect users to malicious websites by manipulating HTTP requests. This affects unauthenticated remote users interacting with vulnerable systems. The vulnerability stems from improper input validation of HTTP parameters.
💻 Affected Systems
- Cisco Evolved Programmable Network Manager (EPNM)
- Cisco Prime Infrastructure
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Users could be redirected to phishing sites that steal credentials or deliver malware, potentially leading to full system compromise if users enter credentials or execute malicious content.
Likely Case
Attackers redirect users to phishing pages to harvest credentials or deliver social engineering attacks, potentially gaining initial access to the network.
If Mitigated
With proper web filtering and user awareness training, impact is limited to failed phishing attempts with minimal operational disruption.
🎯 Exploit Status
Exploitation requires intercepting/modifying HTTP requests, which can be done via man-in-the-middle attacks or malicious links.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific fixed versions
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-epnm-pi-redirect-6sX82dN
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions. 2. Download and apply appropriate patch from Cisco. 3. Restart affected services or appliances as required. 4. Verify patch application and functionality.
🔧 Temporary Workarounds
Restrict Network Access
allLimit access to management interfaces to trusted networks only using firewall rules.
Use VPN for Management
allRequire VPN access before accessing management interfaces to prevent direct exposure.
🧯 If You Can't Patch
- Implement strict web filtering to block known malicious domains and suspicious redirects
- Enable HTTP Strict Transport Security (HSTS) if supported to prevent protocol downgrade attacks
🔍 How to Verify
Check if Vulnerable:
Check system version against Cisco advisory; test for open redirect by attempting to manipulate URL parameters with external domains.Check Version:
Check via web interface admin panel or CLI: 'show version' (specific commands vary by product)Verify Fix Applied:
Verify installed version matches or exceeds patched version; retest vulnerability to confirm redirects are properly validated.📡 Detection & Monitoring
Log Indicators:
- Unusual redirect patterns in web server logs
- HTTP requests with external domains in redirect parameters
- Multiple failed authentication attempts following redirects
Network Indicators:
- HTTP traffic to management interface with suspicious URL parameters
- Outbound connections to unknown domains following management interface access
SIEM Query:
web.url contains "redirect" AND (web.url contains "http://" OR web.url contains external_domain) AND dest_ip IN [management_ips]