CVE-2025-57072 is a high-severity vulnerability identified in the Tenda G3 router firmware version 3.0br_V15.11.0.17. The flaw is a stack overflow occurring in the staticRouteGateway parameter within the formSetStaticRoute function. A stack overflow vulnerability arises when a program writes more data to a buffer located on the stack than it can hold, potentially overwriting adjacent memory. In this case, the vulnerability can be triggered remotely by sending a specially crafted request to the router that manipulates the staticRouteGateway parameter. Exploiting this flaw does not require any authentication or user interaction, and the attacker can cause a Denial of Service (DoS) condition by crashing the device or causing it to become unresponsive. The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow), which is a common and dangerous class of vulnerabilities that can lead to crashes or, in some cases, code execution. However, in this instance, the impact is limited to availability disruption, as there is no indication of confidentiality or integrity compromise. The CVSS v3.1 base score is 7.5, reflecting a high severity due to the network attack vector, low attack complexity, no privileges required, no user interaction, and a scope limited to availability impact. No known exploits have been reported in the wild yet, and no patches have been linked, indicating that mitigation may currently rely on workarounds or vendor updates pending release. The vulnerability affects a specific firmware version of the Tenda G3 router, a consumer-grade networking device commonly used for home and small office internet connectivity. Given the nature of the vulnerability, attackers could disrupt network connectivity for affected users by remotely crashing the router, leading to service outages and potential operational disruptions.

For European organizations, especially small businesses and home offices relying on Tenda G3 routers, this vulnerability poses a significant risk to network availability. A successful exploitation would result in denial of service, causing loss of internet connectivity and disruption of business operations dependent on continuous network access. This could impact remote work, VoIP communications, cloud services access, and other critical online functions. While the vulnerability does not directly compromise data confidentiality or integrity, the resulting downtime could lead to productivity losses and potential financial impact. Additionally, in sectors where network availability is critical, such as healthcare, finance, or public services, even short outages could have cascading effects. The lack of authentication and user interaction requirements makes exploitation easier for attackers, increasing the likelihood of opportunistic attacks. European organizations with limited IT support or outdated network equipment are particularly vulnerable. Furthermore, if attackers combine this DoS vulnerability with other attack vectors, they could use it as a distraction or part of a multi-stage attack. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially once exploit code becomes publicly available.

1. Immediate mitigation should include isolating affected Tenda G3 routers from untrusted networks or restricting access to the router's management interfaces using firewall rules or network segmentation to reduce exposure. 2. Monitor network traffic for unusual or malformed requests targeting the staticRouteGateway parameter or related router management endpoints. 3. Regularly check for firmware updates from Tenda addressing this vulnerability and apply patches promptly once available. 4. If no patch is available, consider replacing affected routers with models from vendors with active security support and timely patching practices. 5. Implement network redundancy where feasible to minimize impact of router outages, such as secondary internet connections or failover devices. 6. Educate IT staff and users about the risks of using outdated or unsupported network devices and encourage proactive device lifecycle management. 7. Employ intrusion detection or prevention systems capable of detecting anomalous requests that may exploit this vulnerability. 8. Maintain up-to-date backups of router configurations to enable rapid recovery or replacement in case of device failure.