CVE-2025-4142 is a critical buffer overflow vulnerability identified in the Netgear EX6200 Wi-Fi range extender, specifically affecting firmware version 1.0.3.94. The vulnerability resides in the function sub_3C8EC, where improper handling of the 'host' argument allows an attacker to overflow a buffer. This flaw can be exploited remotely without requiring user interaction or prior authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L). The vulnerability impacts confidentiality, integrity, and availability at a high level, enabling potential remote code execution or denial of service attacks. The vendor has not responded to disclosure attempts, and no patches or mitigations have been released at the time of publication. Although no known exploits are reported in the wild yet, the ease of exploitation and critical nature of the vulnerability make it a significant threat. The vulnerability's CVSS 4.0 score is 8.7 (high), reflecting its severity and the potential for widespread impact on affected devices. The Netgear EX6200 is a widely deployed consumer and small business networking device, often used to extend wireless coverage, making it a valuable target for attackers aiming to compromise network infrastructure or pivot into internal networks.

For European organizations, the exploitation of CVE-2025-4142 could lead to severe consequences. Compromise of the Netgear EX6200 devices could allow attackers to execute arbitrary code remotely, potentially gaining control over the device and the network segment it serves. This could result in interception or manipulation of network traffic, disruption of wireless connectivity, and unauthorized access to internal systems. Small and medium enterprises (SMEs) and home office environments relying on these extenders may face significant operational disruptions. Additionally, critical infrastructure sectors that utilize such devices for network extension could experience availability issues or data breaches. The lack of vendor response and patches increases the risk exposure, as organizations may be forced to rely on temporary mitigations or device replacement. Given the device's role in network topology, successful exploitation could serve as a foothold for lateral movement within corporate networks, amplifying the potential damage.

1. Immediate network segmentation: Isolate Netgear EX6200 devices from critical network segments to limit potential lateral movement if compromised. 2. Disable remote management features on the EX6200 devices to reduce the attack surface, especially if remote access is not essential. 3. Monitor network traffic for unusual patterns or anomalies originating from or targeting EX6200 devices, using IDS/IPS solutions tailored to detect buffer overflow exploitation attempts. 4. Replace or upgrade affected devices where possible, prioritizing models with updated firmware or alternative hardware from vendors with active security support. 5. Implement strict access control policies and network-level filtering to restrict inbound traffic to the EX6200 devices, allowing only trusted sources. 6. Maintain an inventory of all deployed EX6200 devices and their firmware versions to ensure accurate risk assessment and targeted mitigation. 7. Engage with Netgear support channels and security advisories for updates or patches, and consider coordinated vulnerability disclosure channels to pressure vendor response. 8. Educate IT staff and users about the risks associated with this vulnerability and the importance of applying mitigations promptly.