CVE-2025-67074 is a buffer overflow vulnerability identified in the fromAdvSetMacMtuWan function within the HTTP daemon (httpd) component of Tenda AC10V4.0 routers, specifically version V16.03.10.20. 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 insufficient bounds checking, this crafted input can overflow the buffer, enabling an attacker to cause a denial of service by crashing the httpd process or, more critically, execute arbitrary code remotely. The attack vector is remote and does not require authentication or user interaction, making it accessible to any attacker capable of reaching the device's management interface, typically exposed on the LAN or possibly WAN side depending on configuration. The lack of a CVSS score indicates the vulnerability is newly published with limited public analysis, but the technical details suggest a serious risk. No patches or vendor advisories are currently linked, and no exploits have been reported in the wild, but the vulnerability's nature implies a high potential for exploitation. The affected product, Tenda AC10V4.0 routers, is commonly used in small to medium enterprise and residential environments, which could serve as entry points for attackers targeting broader networks. The vulnerability's exploitation could compromise network integrity, availability, and confidentiality by allowing attackers to disrupt services or implant persistent malware within network infrastructure.

For European organizations, the impact of CVE-2025-67074 could be significant, especially for those relying on Tenda AC10V4.0 routers in their network infrastructure. Exploitation could lead to denial of service, disrupting internet connectivity and internal communications, which can affect business operations and productivity. More severe exploitation involving remote code execution could allow attackers to gain control over the router, enabling interception or manipulation of network traffic, lateral movement within corporate networks, and deployment of further malware or ransomware. This could compromise sensitive data confidentiality and integrity, and potentially lead to regulatory compliance violations under GDPR if personal data is exposed. Small and medium enterprises, which often use consumer-grade routers like Tenda, may be particularly vulnerable due to limited IT security resources. Additionally, critical infrastructure sectors using these devices could face operational disruptions. The absence of known exploits currently provides a window for proactive mitigation, but the ease of exploitation and remote attack vector elevate the risk profile for European organizations.

1. Immediate mitigation should focus on network-level controls: restrict access to router management interfaces by implementing strict firewall rules that limit POST requests to /goform/AdvSetMacMtuWan only from trusted IP addresses. 2. Deploy intrusion detection/prevention systems (IDS/IPS) with custom signatures to detect and block suspicious POST requests containing anomalous 'serverName' payloads. 3. Monitor network traffic for unusual activity or repeated POST requests targeting the vulnerable endpoint. 4. Isolate affected routers from critical network segments until a patch is available. 5. Engage with Tenda support channels to obtain official firmware updates or security advisories; prioritize patching as soon as updates are released. 6. If patching is delayed, consider replacing vulnerable devices with alternative hardware from vendors with robust security support. 7. Educate network administrators about the vulnerability and ensure secure configuration practices, including disabling remote management over WAN if not necessary. 8. Regularly audit router firmware versions and configurations to maintain security hygiene.