CVE-2025-57086 is a stack overflow vulnerability identified in the Tenda W30E router firmware version V16.01.0.19 (build 5037). The flaw exists in the handling of a string parameter within the formDeleteMeshNode function. Specifically, when this function processes a crafted request containing a maliciously constructed string parameter, it triggers a stack overflow condition. This overflow can corrupt the execution stack, leading to unpredictable behavior of the device's firmware. The primary impact of this vulnerability is the ability for an attacker to cause a Denial of Service (DoS) by crashing or rebooting the router, thereby disrupting network connectivity. The vulnerability does not currently have a CVSS score assigned, and there are no known exploits in the wild at this time. The lack of a patch or mitigation guidance from the vendor further increases the risk for affected users. Since the vulnerability is triggered via a crafted request, it likely requires network access to the device's management interface or exposed services that handle mesh node deletion requests. No authentication or user interaction requirements are explicitly mentioned, but the attack vector is presumably remote within the local network or potentially from the internet if the device is misconfigured. The stack overflow nature of the vulnerability suggests that exploitation beyond DoS (such as remote code execution) might be theoretically possible but is not confirmed by the current information.

For European organizations, the impact of this vulnerability primarily manifests as network disruption due to Denial of Service on Tenda W30E routers. Organizations relying on these devices for critical network infrastructure, especially in small to medium-sized enterprises or branch offices, could experience significant downtime affecting business operations, communications, and access to cloud or internal resources. The disruption could also impact remote work capabilities if these routers are used in home office setups. Although no known exploits exist yet, the absence of patches and the potential for attackers to craft malicious requests means that threat actors could develop exploits targeting vulnerable devices. This risk is heightened in environments where network segmentation is weak or where these routers are exposed to untrusted networks. Additionally, the vulnerability could be leveraged as part of a larger attack chain to degrade network reliability or as a distraction while other attacks are conducted. The lack of authentication requirements (if confirmed) would increase the attack surface, making it easier for attackers to trigger the DoS remotely. However, the impact is limited to availability and does not directly compromise confidentiality or integrity based on current knowledge.

To mitigate this vulnerability, European organizations should first identify any deployments of Tenda W30E routers running the affected firmware version V16.01.0.19 (5037). Network administrators should restrict access to the router management interfaces and mesh network functions to trusted internal networks only, employing network segmentation and firewall rules to block unauthorized access. Disabling remote management or mesh node deletion features where not required can reduce the attack surface. Monitoring network traffic for unusual or malformed requests targeting mesh node management APIs may help detect exploitation attempts. Organizations should engage with Tenda support channels to obtain firmware updates or patches addressing this vulnerability and apply them promptly once available. In the interim, consider replacing vulnerable devices with alternative hardware if critical services depend on them. Additionally, implementing network-level DoS protection and maintaining robust incident response plans will help minimize operational impact if exploitation occurs.