CVE-2020-11900 – CVE-2020-11900 is a double-free vulnerability i... (How to Fix)

Q: What is the severity of CVE-2020-11900?

CVE-2020-11900 has a CVSS score of 8.2 (HIGH). CVE-2020-11900 is a double-free vulnerability in the Treck TCP/IP stack's IPv4 tunneling implementation that allows remote attackers to execute arbitrary code or cause denial of service. This affects numerous embedded systems, networking devices, and IoT products from multiple vendors that use the vulnerable Treck stack. Organizations using affected products from Aruba, Cisco, HPE, NetApp, and other vendors are at risk.

📋 TL;DR

CVE-2020-11900 is a double-free vulnerability in the Treck TCP/IP stack's IPv4 tunneling implementation that allows remote attackers to execute arbitrary code or cause denial of service. This affects numerous embedded systems, networking devices, and IoT products from multiple vendors that use the vulnerable Treck stack. Organizations using affected products from Aruba, Cisco, HPE, NetApp, and other vendors are at risk.

💻 Affected Systems

Products:

Aruba switches/routers
Cisco networking devices
HPE servers/storage
NetApp storage systems
Various embedded/IoT devices using Treck stack

Versions: Treck TCP/IP stack versions before 6.0.1.41

Operating Systems: Embedded systems, Network appliances, IoT devices

Default Config Vulnerable: ⚠️ Yes

Notes: Affects any device using the vulnerable Treck TCP/IP stack implementation. Many vendors have specific affected product lists in their advisories.

📦 What is this software?

Tcp\/ip by Treck

View all CVEs affecting Tcp\/ip →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data exfiltration, and lateral movement within networks.

🟠

Likely Case

Denial of service causing system crashes and network disruption, potentially leading to operational downtime.

🟢

If Mitigated

Limited impact if proper network segmentation and access controls prevent external exploitation attempts.

🌐 Internet-Facing: HIGH - Remote exploitation possible without authentication via crafted IPv4 tunneling packets.

🏢 Internal Only: MEDIUM - Internal attackers could exploit, but requires network access to vulnerable systems.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires sending specially crafted IPv4 tunneling packets. Multiple vendors have confirmed the vulnerability is exploitable.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Treck TCP/IP stack 6.0.1.41 or later

Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-treck-ip-stack-JyBQ5GyC

Restart Required: Yes

Instructions:

1. Check vendor-specific advisory for affected products. 2. Apply vendor-provided firmware/software updates. 3. Reboot affected devices after patching. 4. Verify patch installation.

🔧 Temporary Workarounds

Network segmentation

all

Isolate affected devices from untrusted networks and limit access to necessary services only.

Firewall rules

all

Block IPv4 tunneling protocols at network perimeter if not required for operations.

🧯 If You Can't Patch

Implement strict network access controls to limit exposure to trusted sources only
Monitor network traffic for anomalous IPv4 tunneling activity and implement intrusion detection

🔍 How to Verify

Check if Vulnerable:

Check device firmware/software version against vendor-specific affected version lists in advisories.

Check Version:

Vendor-specific - typically via device CLI or management interface (e.g., 'show version' on Cisco devices)

Verify Fix Applied:

Verify installed version is patched (Treck 6.0.1.41+ or vendor-specific fixed version).

📡 Detection & Monitoring

Log Indicators:

System crashes
Memory corruption errors
Unexpected reboots
IPv4 tunneling protocol errors

Network Indicators:

Malformed IPv4 tunneling packets
Unusual traffic patterns to vulnerable ports
Exploit attempt signatures

SIEM Query:

Search for: (event_type:crash OR error:memory) AND (process:treck OR component:ip_stack) OR (network.protocol:ipv4_tunnel AND anomaly_score>threshold)

📊 Metadata

CVE ID: CVE-2020-11900

CVSS v3 Score: 8.2 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

CWE: CWE-415

Published: June 17, 2020

Last Updated: November 21, 2024

🔗 References

http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-006.txt
https://jsof-tech.com/vulnerability-disclosure-policy/ Third Party Advisory
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 Third Party Advisory
https://www.dell.com/support/article/de-de/sln321836/dell-response-to-the-ripple20-vulnerabilities
https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00295.html Not Applicable,Third Party Advisory
https://www.jsof-tech.com/ripple20/ Exploit,Third Party Advisory
https://www.kb.cert.org/vuls/id/257161
https://www.kb.cert.org/vuls/id/257161/ Mitigation,Third Party Advisory,US Government Resource
https://www.treck.com Product,Vendor Advisory
http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-006.txt
https://jsof-tech.com/vulnerability-disclosure-policy/ Third Party Advisory
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 Third Party Advisory
https://www.dell.com/support/article/de-de/sln321836/dell-response-to-the-ripple20-vulnerabilities
https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00295.html Not Applicable,Third Party Advisory
https://www.jsof-tech.com/ripple20/ Exploit,Third Party Advisory
https://www.kb.cert.org/vuls/id/257161
https://www.kb.cert.org/vuls/id/257161/ Mitigation,Third Party Advisory,US Government Resource
https://www.treck.com Product,Vendor Advisory

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