CVE-2021-45917
📋 TL;DR
This vulnerability allows an authenticated attacker on the local network to perform server-side request forgery (SSRF) attacks against other agent computers in the Shockwall system. This can lead to arbitrary code execution, potentially giving the attacker control over affected systems or disrupting services. Only authenticated users within the local network can exploit this vulnerability.
💻 Affected Systems
- Shockwall system
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over affected Shockwall agent systems, potentially leading to lateral movement across the network, data exfiltration, or service disruption.
Likely Case
Unauthorized access to internal systems, data leakage from internal services, and potential privilege escalation within the Shockwall environment.
If Mitigated
Limited impact due to network segmentation and proper authentication controls, potentially only affecting isolated systems with minimal critical data.
🎯 Exploit Status
Exploitation requires authenticated access and local network positioning. The SSRF to RCE chain suggests moderate complexity but significant impact potential.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in available references
Vendor Advisory: https://www.twcert.org.tw/tw/cp-132-5433-77f6f-1.html
Restart Required: Yes
Instructions:
1. Contact Shockwall vendor for specific patch information. 2. Apply the latest security updates provided by the vendor. 3. Restart affected systems as required by the patch. 4. Verify the fix by testing the authentication mechanism.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Shockwall agent systems from other critical infrastructure to limit lateral movement potential
Enhanced Authentication Controls
allImplement multi-factor authentication and strict access controls for Shockwall administrative interfaces
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Shockwall systems from critical assets
- Enhance monitoring and logging of authentication attempts and server requests within the Shockwall environment
🔍 How to Verify
Check if Vulnerable:
Check Shockwall system version against vendor advisory. Monitor for unauthorized server requests between agent systems.Check Version:
Check Shockwall administrative interface or contact vendor for version verification commandVerify Fix Applied:
Test authentication mechanisms and verify that server requests are properly validated. Check that patch version matches vendor recommendations.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication patterns
- Unexpected server requests between agent systems
- SSRF attempt patterns in request logs
Network Indicators:
- Unusual traffic between Shockwall agent systems
- Requests to internal services from unexpected sources
SIEM Query:
source="shockwall" AND (event_type="authentication" OR event_type="server_request") AND status="failed"