CVE-2020-11914: Treck TCP/IP ARP Information Disclosure

CVE-2020-11914 Overview

CVE-2020-11914 is an out-of-bounds read vulnerability in the Treck TCP/IP stack before version 6.0.1.66. The flaw exists within the ARP (Address Resolution Protocol) packet processing functionality, allowing an attacker on an adjacent network to read memory beyond the intended buffer boundaries. This vulnerability is part of the broader "Ripple20" collection of vulnerabilities discovered in the Treck TCP/IP stack, which affects millions of IoT and embedded devices worldwide.

Critical Impact

This vulnerability enables information disclosure from affected devices on local networks. Due to the widespread deployment of Treck's TCP/IP stack in industrial control systems, medical devices, transportation systems, and enterprise equipment, the potential attack surface is extensive across critical infrastructure sectors.

Affected Products

• Treck TCP/IP stack versions prior to 6.0.1.66
• Devices from multiple vendors incorporating vulnerable Treck TCP/IP implementations including Cisco, HPE, Dell, Aruba Networks, and NetApp
• IoT and embedded systems utilizing the affected Treck networking components

Discovery Timeline

• June 17, 2020 - CVE-2020-11914 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2020-11914

Vulnerability Analysis

This vulnerability stems from improper bounds checking in the ARP packet handling code within the Treck TCP/IP stack. When processing ARP requests or responses, the stack fails to properly validate the length of incoming data before reading from the packet buffer. This allows an attacker to craft malicious ARP packets that trigger reads beyond the allocated memory region, potentially exposing sensitive information stored in adjacent memory locations.

The vulnerability requires the attacker to be on the same network segment as the target device (adjacent network access), which limits remote exploitation but makes it highly relevant in enterprise and industrial network environments where lateral movement is a concern.

Root Cause

The root cause is a classic CWE-125 (Out-of-bounds Read) issue where the ARP processing function does not adequately verify that the data being accessed falls within the legitimate boundaries of the received packet buffer. The code trusts length fields or makes assumptions about packet structure without proper validation, leading to memory access violations that can leak information.

Attack Vector

The attack vector requires adjacent network access, meaning the attacker must be on the same local network segment as the vulnerable device. Exploitation does not require authentication or user interaction, and can be performed by sending specially crafted ARP packets to the target system.

An attacker would construct malformed ARP packets with manipulated length fields or payload structures designed to cause the vulnerable code to read beyond the intended buffer. The information disclosed could include:

• Memory contents from adjacent buffers
• Potential cryptographic material or credentials stored in memory
• Internal state information useful for further exploitation

While no verified proof-of-concept code is publicly available for this specific vulnerability, the attack involves crafting ARP packets that trigger out-of-bounds memory reads in the Treck TCP/IP stack's packet processing logic. Technical details can be found in the JSOF Ripple20 Overview and the CERT Vulnerability ID #257161.

Detection Methods for CVE-2020-11914

Indicators of Compromise

• Unusual or malformed ARP traffic on local network segments
• Anomalous ARP packet sizes or structures that deviate from standard specifications
• Unexpected ARP requests or replies from suspicious sources
• Memory access violations or crashes in network stack processes

Detection Strategies

• Deploy network intrusion detection systems (IDS) with signatures for malformed ARP packets
• Monitor for ARP traffic anomalies including unusual packet lengths and malformed headers
• Implement asset inventory scanning to identify devices running vulnerable Treck TCP/IP stack versions
• Use network segmentation monitoring to detect lateral movement attempts

Monitoring Recommendations

• Enable detailed logging on network devices and security appliances for ARP-related events
• Configure SIEM alerts for patterns consistent with ARP-based reconnaissance or exploitation attempts
• Conduct regular vulnerability assessments of IoT and embedded devices on the network
• Monitor vendor security advisories from affected manufacturers for updated guidance

How to Mitigate CVE-2020-11914

Immediate Actions Required

• Inventory all devices that may utilize the Treck TCP/IP stack in your environment
• Apply vendor-provided firmware updates and patches as they become available
• Implement network segmentation to isolate vulnerable devices from untrusted network segments
• Disable or block ARP traffic where operationally feasible using network access controls

Patch Information

The vulnerability is addressed in Treck TCP/IP stack version 6.0.1.66 and later. Organizations should consult their device vendors for firmware updates that incorporate the patched Treck library. Multiple vendors have issued security advisories:

• CERT Vulnerability ID #257161 - Coordination center advisory
• Cisco Security Advisory for Treck IP Stack - Cisco product guidance
• HPE Security Document - HPE affected products
• Aruba Networks Security Alert - Aruba product guidance
• Dell Response to Ripple20 Vulnerabilities - Dell product information
• NetApp Security Advisory NTAP-20200625-0006 - NetApp guidance

Workarounds

• Implement strict network segmentation to limit adjacent network access to vulnerable devices
• Deploy network access control (NAC) solutions to restrict which systems can communicate with affected devices
• Use static ARP entries where feasible to prevent ARP-based attacks
• Consider deploying intrusion prevention systems (IPS) with Ripple20 detection signatures

# Example: Network segmentation using VLAN isolation for vulnerable IoT devices
# Create dedicated VLAN for IoT/embedded devices
vlan 100
  name IOT_ISOLATED

# Apply strict ACLs to limit traffic to/from vulnerable devices
access-list 100 permit ip host 192.168.100.0 0.0.0.255 host 192.168.1.10
access-list 100 deny ip any 192.168.100.0 0.0.0.255