CVE-2025-67074 is a buffer overflow vulnerability identified in the fromAdvSetMacMtuWan function of the HTTP daemon (httpd) component on Tenda AC10V4.0 routers with firmware version 16.03.10.20. The vulnerability arises when the device processes a POST request to the /goform/AdvSetMacMtuWan endpoint containing a specially crafted payload in the serverName field. Due to improper bounds checking, the crafted input can overflow the buffer, leading to memory corruption. This can cause the device to crash, resulting in denial of service (DoS), or potentially allow an attacker to execute arbitrary code remotely. The attack vector is network-based, requiring only access to the router's HTTP management interface, which may be exposed on local or WAN networks depending on configuration. No authentication or user interaction is required, increasing the risk if the interface is exposed externally. The CVSS 3.1 base score is 6.5, reflecting medium severity with attack vector as adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and impact limited to availability (A:H) without confidentiality or integrity impact. No patches or known exploits are currently available, but the vulnerability is classified under CWE-120 (classic buffer overflow). The lack of affected version details beyond the firmware version suggests limited scope but significant risk for users of this specific router model and firmware. The vulnerability could be exploited by attackers to disrupt network connectivity or potentially gain control over the device, which could be leveraged for further attacks within a network.

For European organizations, the primary impact of CVE-2025-67074 is the potential denial of service on affected Tenda AC10V4.0 routers, which could disrupt internet connectivity or internal network operations. In environments where these routers serve as gateways or critical network infrastructure, this could lead to operational downtime and productivity loss. Although the vulnerability currently has no confirmed exploits in the wild, the possibility of remote code execution elevates the risk, as attackers could gain persistent access to the network or pivot to other internal systems. Organizations relying on these devices for remote or branch office connectivity may face increased exposure, especially if the router's management interface is accessible from untrusted networks. The lack of confidentiality or integrity impact reduces the risk of data breaches directly from this vulnerability, but service disruption and potential device compromise remain significant concerns. European entities with limited IT support or delayed patching processes may be particularly vulnerable to exploitation once public exploits emerge.

European organizations should immediately audit their network infrastructure to identify the presence of Tenda AC10V4.0 routers running firmware version 16.03.10.20. If identified, restrict access to the router's management interface by implementing network segmentation and firewall rules to limit access to trusted internal IPs only. Disable remote management over WAN if enabled. Monitor network traffic for suspicious POST requests targeting the /goform/AdvSetMacMtuWan endpoint, especially those containing unusual or oversized serverName fields. Until an official patch is released, consider replacing vulnerable devices with updated models or alternative vendors with active security support. Employ network intrusion detection systems (NIDS) with custom signatures to detect exploitation attempts. Maintain up-to-date backups of router configurations to enable rapid recovery in case of device failure. Engage with Tenda support channels to obtain firmware updates or security advisories. Educate IT staff on the specific risks and signs of exploitation related to this vulnerability to enhance incident response readiness.