CVE-2021-31932
📋 TL;DR
This vulnerability allows unauthenticated attackers to bypass authentication on Nokia BTS TRS web consoles by using URL encoding for the dot character. Attackers can access all web panel functionalities without credentials. Organizations using affected Nokia transport modules are at risk.
💻 Affected Systems
- Nokia BTS TRS (Transport Module)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the transport module allowing configuration changes, service disruption, and potential lateral movement to connected telecom infrastructure.
Likely Case
Unauthorized access to sensitive configuration data, monitoring information, and potential service manipulation.
If Mitigated
Limited impact if network segmentation prevents external access and strict access controls are in place.
🎯 Exploit Status
Exploit involves simple URL manipulation with dot character encoding. Public exploit code exists in Packet Storm references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown - Nokia has not published public advisory
Restart Required: No
Instructions:
No official patch available. Contact Nokia support for guidance. Consider upgrading to latest firmware if available.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Nokia transport modules from untrusted networks and restrict access to authorized management networks only.
Web Console Access Restriction
allImplement firewall rules to block external access to the web console port (typically HTTP/HTTPS).
🧯 If You Can't Patch
- Implement strict network access controls allowing only authorized IP addresses to access the web console
- Monitor for unusual authentication bypass attempts and URL encoding patterns in web logs
🔍 How to Verify
Check if Vulnerable:
Attempt to access protected web console pages using URL-encoded dot characters (e.g., %2E instead of .) without authentication.Check Version:
Check web console interface or system information page for version FTM_W20_FP2_2019.08.16_0010 or similarVerify Fix Applied:
Verify that URL encoding techniques no longer bypass authentication and proper login is required for all protected pages.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful access without proper login
- Requests containing URL-encoded dot characters (%2E) to protected resources
Network Indicators:
- Unauthenticated HTTP requests to administrative endpoints
- Traffic patterns showing access to multiple protected pages without authentication sequences
SIEM Query:
web.url CONTAINS "%2E" AND (web.status_code = 200 OR web.status_code = 302) AND NOT auth.success = true