CVE-2025-7615 is a command injection vulnerability identified in the TOTOLINK T6 router firmware version 4.1.5cu.748. The vulnerability resides in the HTTP POST request handler, specifically within the clearPairCfg function of the /cgi-bin/cstecgi.cgi endpoint. An attacker can manipulate the 'ip' argument in the POST request to inject arbitrary system commands. This vulnerability can be exploited remotely without requiring user interaction or prior authentication, making it a significant risk. The CVSS 4.0 base score is 5.3 (medium severity), reflecting that while the attack vector is network-based and requires no user interaction, it does require low privileges (PR:L) and results in low impact on confidentiality, integrity, and availability. The vulnerability has been publicly disclosed, although there are no known exploits currently observed in the wild. The lack of authentication requirement and the ability to execute arbitrary commands on the device could allow attackers to take control of the router, potentially leading to network compromise, interception of traffic, or pivoting to internal systems. The TOTOLINK T6 is a consumer-grade wireless router, and the vulnerability affects a specific firmware version, indicating that devices not updated or patched remain at risk. The absence of an official patch link suggests that users and administrators should monitor vendor communications for updates or consider alternative mitigations.

For European organizations, this vulnerability poses a risk primarily to small and medium enterprises (SMEs) and home office environments that deploy TOTOLINK T6 routers. Successful exploitation could lead to unauthorized control over network infrastructure, enabling attackers to intercept sensitive communications, launch further attacks within the internal network, or disrupt network availability. Given the router's role as a gateway device, compromise could undermine the confidentiality and integrity of organizational data flows. While the medium CVSS score suggests limited direct impact on core enterprise systems, the router's compromise could serve as a foothold for more extensive attacks. Additionally, organizations in sectors with stringent data protection requirements (e.g., finance, healthcare) could face compliance risks if network devices are compromised. The public disclosure of the vulnerability increases the likelihood of exploitation attempts, emphasizing the need for timely mitigation. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate it, especially as exploit code may emerge following disclosure.

1. Immediate mitigation should include isolating affected TOTOLINK T6 devices from critical network segments to limit potential lateral movement. 2. Network administrators should implement strict access controls on management interfaces, restricting access to trusted IP addresses and disabling remote management if not required. 3. Monitor network traffic for unusual POST requests to /cgi-bin/cstecgi.cgi, particularly those containing suspicious 'ip' parameter values indicative of command injection attempts. 4. Employ network intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect exploitation attempts targeting this vulnerability. 5. Regularly check for firmware updates from TOTOLINK and apply patches as soon as they become available. 6. Consider replacing vulnerable devices with alternative routers from vendors with robust security update policies if patches are delayed. 7. Educate users and IT staff about the risks of using outdated firmware and the importance of timely updates. 8. Implement network segmentation to limit exposure of critical assets in case of router compromise.