CVE-2025-7952 is a command injection vulnerability identified in the TOTOLINK T6 router, specifically in version 4.1.5cu.748. The flaw resides in the function ckeckKeepAlive within the wireless.so component, which handles MQTT packets. MQTT (Message Queuing Telemetry Transport) is a lightweight messaging protocol commonly used in IoT and networking devices for telemetry and control. The vulnerability allows an attacker to remotely inject arbitrary commands due to insufficient input validation or sanitization in the MQTT packet handler. This can lead to execution of unauthorized commands on the device's underlying operating system. The vulnerability does not require user interaction and can be exploited remotely without authentication, increasing its risk profile. However, the CVSS 4.0 base score is 5.3 (medium severity), reflecting some mitigating factors such as limited impact on confidentiality, integrity, and availability (all rated low), and the requirement of low privileges (PR:L) to exploit. The exploit has been publicly disclosed but there are no known exploits actively used in the wild at this time. The vulnerability affects only the specific firmware version 4.1.5cu.748 of TOTOLINK T6 devices. No official patches or mitigation links have been provided yet. Given the nature of command injection, successful exploitation could allow attackers to execute arbitrary system commands, potentially leading to device compromise, network pivoting, or disruption of network services managed by the router.

For European organizations, the impact of this vulnerability depends on the deployment scale of TOTOLINK T6 routers within their infrastructure. If these devices are used in enterprise or critical network environments, exploitation could lead to unauthorized control over network routing, interception or manipulation of network traffic, and potential lateral movement within internal networks. This could compromise confidentiality and integrity of sensitive data and disrupt availability of network services. Small and medium enterprises or home office setups using these routers are also at risk, potentially exposing personal or business data. Since the vulnerability allows remote command execution without user interaction, attackers could automate attacks at scale. The medium CVSS score suggests limited but non-negligible risk, especially if combined with other vulnerabilities or weak network segmentation. The absence of known active exploits reduces immediate threat but public disclosure increases risk of future exploitation. European organizations should assess their use of TOTOLINK T6 devices and prioritize mitigation to prevent potential compromise.

1. Immediate inventory and identification of all TOTOLINK T6 devices running firmware version 4.1.5cu.748 within the organization's network. 2. Restrict remote access to management interfaces of these routers, especially MQTT-related services, by implementing network segmentation and firewall rules to limit exposure to untrusted networks. 3. Disable or restrict MQTT services on the device if not required for operational purposes. 4. Monitor network traffic for unusual MQTT packets or command injection patterns targeting the wireless.so component. 5. Apply any available firmware updates or patches from TOTOLINK as soon as they are released. In the absence of official patches, consider temporary mitigations such as disabling vulnerable features or replacing affected devices with alternative hardware. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures for MQTT command injection attempts. 7. Educate network administrators about this vulnerability and ensure strong authentication and access controls are in place for device management. 8. Regularly review and update device firmware and configurations to minimize attack surface.