CVE-2020-11896
📋 TL;DR
CVE-2020-11896 is a critical remote code execution vulnerability in the Treck TCP/IP stack affecting IPv4 tunneling. Attackers can exploit this flaw to execute arbitrary code on vulnerable systems, potentially gaining full control. This affects numerous embedded devices, networking equipment, and IoT devices from multiple vendors that use the vulnerable Treck stack.
💻 Affected Systems
- Aruba switches/routers
- Siemens industrial devices
- NetApp storage systems
- HPE networking equipment
- Various embedded/IoT devices using Treck stack
📦 What is this software?
Tcp\/ip by Treck
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install persistent malware, pivot to internal networks, exfiltrate sensitive data, or render devices inoperable.
Likely Case
Remote code execution leading to device takeover, network disruption, or deployment of ransomware/botnets on vulnerable systems.
If Mitigated
Limited impact if systems are isolated, patched, or have network controls preventing exploitation attempts.
🎯 Exploit Status
Exploitation requires sending specially crafted IPv4 tunneling packets to vulnerable systems. Multiple threat actors have weaponized this vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Treck TCP/IP stack 6.0.1.66 or later
Vendor Advisory: http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-006.txt
Restart Required: Yes
Instructions:
1. Check vendor advisories for specific patches. 2. Apply vendor-provided firmware updates. 3. Reboot affected devices. 4. Verify patch installation.
🔧 Temporary Workarounds
Network segmentation
allIsolate vulnerable devices from untrusted networks
Firewall rules
allBlock IPv4 tunneling traffic to vulnerable devices
🧯 If You Can't Patch
- Segment vulnerable devices in isolated network zones
- Implement strict firewall rules to block all IPv4 tunneling traffic
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against vendor advisories. Use vulnerability scanners with CVE-2020-11896 detection.Check Version:
Vendor-specific commands vary. Consult device documentation for firmware version check.Verify Fix Applied:
Verify firmware version is updated to patched version per vendor guidance. Test with vulnerability scanner.📡 Detection & Monitoring
Log Indicators:
- Unusual IPv4 tunneling traffic
- Multiple connection attempts to vulnerable ports
- System crash or reboot logs
Network Indicators:
- Malformed IPv4 tunneling packets
- Exploit traffic patterns matching known PoCs
SIEM Query:
source_ip=* AND dest_ip=vulnerable_device AND protocol=ipv4_tunnel AND packet_size=anomalous🔗 References
- http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-006.txt
- https://cert-portal.siemens.com/productcert/pdf/ssa-631949.pdf
- https://jsof-tech.com/vulnerability-disclosure-policy/
- https://security.netapp.com/advisory/ntap-20200625-0006/
- https://support.hpe.com/hpesc/public/docDisplay?docLocale=en_US&docId=hpesbhf04012en_us
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-treck-ip-stack-JyBQ5GyC
- https://www.dell.com/support/article/de-de/sln321836/dell-response-to-the-ripple20-vulnerabilities
- https://www.jsof-tech.com/ripple20/
- https://www.kb.cert.org/vuls/id/257161
- https://www.kb.cert.org/vuls/id/257161/
- https://www.treck.com
- http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-006.txt
- https://cert-portal.siemens.com/productcert/pdf/ssa-631949.pdf
- https://jsof-tech.com/vulnerability-disclosure-policy/
- https://security.netapp.com/advisory/ntap-20200625-0006/
- https://support.hpe.com/hpesc/public/docDisplay?docLocale=en_US&docId=hpesbhf04012en_us
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-treck-ip-stack-JyBQ5GyC
- https://www.dell.com/support/article/de-de/sln321836/dell-response-to-the-ripple20-vulnerabilities
- https://www.jsof-tech.com/ripple20/
- https://www.kb.cert.org/vuls/id/257161
- https://www.kb.cert.org/vuls/id/257161/
- https://www.treck.com
