CVE-2025-57062 is a stack overflow vulnerability identified in the Tenda G3 router firmware version 3.0br_V15.11.0.17. The flaw exists in the handling of the delDhcpIndex parameter within the formDelDhcpRule function. Specifically, when processing this parameter, the firmware fails to properly validate input length or content, leading to a stack overflow condition. An attacker can exploit this vulnerability by sending a specially crafted request to the affected router, triggering the overflow. The primary consequence of this vulnerability is a Denial of Service (DoS) condition, where the router may crash or become unresponsive, disrupting network connectivity. There is no indication that this vulnerability allows for remote code execution or privilege escalation, and no known exploits have been reported in the wild as of the publication date. The vulnerability affects a specific firmware version of the Tenda G3 router, a consumer-grade networking device commonly used in home and small office environments. The lack of a CVSS score suggests that the vulnerability has not yet been fully assessed for severity, but the technical details confirm the potential for service disruption via crafted network requests.

For European organizations, especially small businesses and home offices relying on Tenda G3 routers, this vulnerability poses a risk of network downtime due to DoS attacks. Disruption of internet connectivity can impact business operations, remote work capabilities, and access to cloud services. While the vulnerability does not appear to allow data breach or device takeover, the loss of availability can degrade productivity and potentially interrupt critical communications. In environments where network uptime is essential, such as small healthcare practices or remote work setups, this could have significant operational consequences. Additionally, if exploited in a coordinated manner, attackers could target multiple vulnerable devices to create larger-scale network disruptions. However, the impact is somewhat limited by the requirement to send crafted requests directly to the vulnerable device, which may require network access or prior compromise of the local network.

Organizations should immediately verify if their network infrastructure includes Tenda G3 routers running firmware version 3.0br_V15.11.0.17. If so, they should seek firmware updates or patches from Tenda as a priority, even though no patch links are currently published. In the absence of an official patch, network administrators should implement access controls to restrict management interface access to trusted IP addresses only, ideally limiting it to internal networks or VPN connections. Deploying network-level intrusion detection or prevention systems (IDS/IPS) that can detect anomalous or malformed DHCP-related requests may help mitigate exploitation attempts. Regular monitoring of router logs for unusual activity related to DHCP rule modifications is recommended. Additionally, organizations should consider segmenting vulnerable devices from critical network segments to reduce potential impact. Users should also consider replacing outdated or unsupported devices with models that receive regular security updates.