Second Order Command-injection Vulnerability in the Key-generation Function

Vulnerability

A command injection vulnerability exists in the key-generation function of TN-5900 Series firmware versions v3.3 and prior [1]. The flaw stems from insufficient input validation and improper authentication, allowing an attacker to inject arbitrary commands through the web server [1].

Exploitation

An attacker with network access to the affected device can send specially crafted requests to the key-generation endpoint without authentication [1]. By manipulating input parameters, arbitrary operating system commands can be injected and executed [1].

Impact

Successful exploitation enables remote code execution with the privileges of the web server, typically root or system-level access [1]. This compromises confidentiality, integrity, and availability of the device and potentially the network it serves.

Mitigation

Moxa has not yet released a fixed firmware version for TN-5900 Series [1]. As a workaround, minimize network exposure by ensuring the device is not accessible from the Internet, and use VPNs for remote access [1].