CVE-2020-11909

Vulnerability

The Treck TCP/IP stack versions before 6.0.1.66 contain an integer underflow vulnerability in the IPv4 module [1]. This bug is part of the Ripple20 set of vulnerabilities affecting embedded systems using the Treck stack [1]. The integer underflow occurs when processing specially crafted IPv4 packets, leading to memory corruption.

Exploitation

An unauthenticated remote attacker can send a specially crafted IPv4 packet to a device running the vulnerable Treck stack [1]. No authentication or user interaction is required. The attacker only needs network access to the target device. The integer underflow can cause the stack to misinterpret packet length fields, potentially leading to buffer overflows.

Impact

Successful exploitation could allow an attacker to cause denial of service, disclose sensitive information, or execute arbitrary code on the affected device [1]. The exact impact depends on the device's configuration and the Treck stack integration. Given the widespread use of Treck in embedded systems (e.g., medical devices, industrial control), the impact can be severe [1].

Mitigation

Treck released version 6.0.1.67 to address this vulnerability [1]. Users should update to the latest stable version. Downstream vendors (e.g., Dell, Cisco) have issued advisories and patches for their products [3][4]. If patching is not immediately possible, network administrators can block anomalous IP traffic using deep packet inspection or firewall rules to drop malformed packets [1]. The vulnerability is part of the Ripple20 set, and CERT/CC recommends contacting the device vendor for specific updates [1].