CVE-2020-11898

Vulnerability

CVE-2020-11898 affects the Treck TCP/IP stack, versions prior to 6.0.1.66. The vulnerability arises from improper handling of an inconsistency between the IPv4 header length and the ICMPv4 header length when processing network packets. This issue is part of the Ripple20 set of vulnerabilities identified by JSOF and affects numerous embedded systems that integrate the Treck stack, as reported by CERT/CC [1][2].

Exploitation

An unauthenticated remote attacker can send a specially crafted network packet that triggers the length inconsistency. No authentication or prior access is required; the attacker only needs network connectivity to a device using the vulnerable Treck stack. The malformed packet causes the stack to process the inconsistent length fields incorrectly, potentially leading to memory out-of-bounds read. While specific exploit steps are not publicly detailed, the attack vector is network-based and does not require user interaction [1][2].

Impact

Successful exploitation may allow the attacker to trigger an information leak, potentially disclosing sensitive data from the device's memory. The scope is limited to information disclosure; however, due to the diversity of implementations, other impacts (such as denial of service or arbitrary code execution) cannot be ruled out for some configurations, as noted in the broader Ripple20 analysis [1][2].

Mitigation

Update the Treck IP stack to version 6.0.1.67 or later, as recommended by CERT/CC [1]. Downstream users of embedded systems (including those from Cisco, Dell, and other vendors) should contact their equipment vendor for specific patches. Cisco has provided fixed releases for affected products and Snort rules to detect exploitation attempts [4]. Dell has issued updates for client platforms and Teradici firmware [3]. Network segmentation and deep packet inspection can act as workarounds to block malformed packets [1].