CVE-2025-65202 identifies a critical authenticated remote OS command injection vulnerability in the TRENDnet TEW-657BRM router firmware version 1.00.1. The vulnerability resides in the setup.cgi binary, which processes HTTP requests containing the parameters "command", "todo", and "next_file". An attacker with valid authentication credentials can manipulate these parameters to inject arbitrary shell commands executed with root privileges on the device. This allows full control over the router, enabling actions such as configuration changes, network traffic interception, or pivoting to internal networks. The vulnerability is classified under CWE-78 (Improper Neutralization of Special Elements used in an OS Command), indicating a failure to properly sanitize user input before command execution. The CVSS v3.1 base score is 8.0, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and no user interaction required beyond authentication. Although no public exploits are currently reported, the presence of remote authenticated command injection in a network device firmware is a serious risk, especially if default or weak credentials are used. The lack of available patches at the time of disclosure increases exposure. This vulnerability highlights the importance of secure coding practices in embedded device management interfaces and the risks posed by remotely accessible administrative functions.

For European organizations, exploitation of this vulnerability could lead to complete compromise of affected routers, resulting in unauthorized access to internal networks, interception or manipulation of sensitive data, disruption of network services, and potential lateral movement to other critical systems. Given the root-level access gained, attackers could install persistent backdoors or launch further attacks against connected infrastructure. Organizations relying on TRENDnet TEW-657BRM devices for network connectivity or remote access are particularly at risk. Critical sectors such as finance, healthcare, energy, and government may face severe operational disruptions and data breaches. The vulnerability’s requirement for authentication reduces risk somewhat but does not eliminate it, as credential theft or default passwords remain common attack vectors. The absence of known exploits currently provides a window for proactive mitigation, but the high severity score underscores the urgency of addressing this issue. Remote management features exposed to the internet increase the attack surface, making organizations with less restrictive network policies more vulnerable.

1. Immediately restrict access to the router’s management interface by limiting it to trusted internal networks and disabling remote management if not essential. 2. Enforce strong, unique passwords for all administrative accounts and disable default credentials. 3. Monitor router logs and network traffic for unusual commands or access patterns indicative of exploitation attempts. 4. Implement network segmentation to isolate critical systems from devices running vulnerable firmware. 5. Regularly audit and update device firmware; coordinate with TRENDnet for timely patch releases addressing this vulnerability. 6. Employ multi-factor authentication for device management where supported to reduce risk from credential compromise. 7. Use intrusion detection/prevention systems to detect anomalous HTTP requests targeting the vulnerable parameters. 8. Educate network administrators about this vulnerability and the importance of secure device configuration. 9. Consider replacing affected devices with models from vendors with stronger security track records if patches are delayed or unavailable.