CVE-2025-11525 is a stack-based buffer overflow vulnerability identified in the Tenda AC7 router firmware version 15.03.06.44. The vulnerability resides in an unspecified function handling the /goform/SetUpnpCfg endpoint, specifically through improper handling of the upnpEn parameter. By sending a crafted request to this endpoint, an attacker can overflow the stack buffer, potentially overwriting control data such as return addresses or function pointers. This can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly accessible to attackers scanning for vulnerable devices exposed to the internet or internal networks. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no privileges or user interaction needed. Although no known exploits are currently active in the wild, the public disclosure of exploit details increases the likelihood of imminent exploitation attempts. The affected product, Tenda AC7, is a consumer-grade Wi-Fi 6 router commonly used in small office and home office environments, which may be deployed in European organizations with less stringent network security controls. The vulnerability's exploitation could allow attackers to gain persistent footholds within networks, intercept or manipulate traffic, or disrupt network availability. The lack of available patches at the time of disclosure necessitates immediate risk mitigation through network segmentation, access controls, and monitoring for suspicious activity targeting the vulnerable endpoint.

For European organizations, the exploitation of CVE-2025-11525 could lead to severe consequences including unauthorized remote code execution on network routers, enabling attackers to intercept, modify, or redirect network traffic. This compromises confidentiality and integrity of sensitive communications. Additionally, successful exploitation could cause denial of service by crashing the device, impacting availability of critical network infrastructure. Small and medium enterprises relying on Tenda AC7 routers without robust network segmentation or monitoring are particularly vulnerable. The ability to exploit this vulnerability remotely without authentication increases the attack surface, especially for organizations with routers exposed to the internet or poorly secured internal networks. Compromise of these routers could facilitate lateral movement within corporate networks, potentially leading to broader intrusions affecting enterprise IT systems. Given the critical role of network devices in maintaining secure communications, this vulnerability poses a significant risk to operational continuity and data protection compliance obligations under European regulations such as GDPR.

1. Immediately check for and apply any firmware updates or patches released by Tenda addressing CVE-2025-11525. 2. If patches are not yet available, restrict access to the router's management interfaces, especially the /goform/SetUpnpCfg endpoint, by implementing firewall rules to block inbound traffic from untrusted networks. 3. Disable UPnP functionality on the Tenda AC7 routers if not required, as the vulnerability is related to the UPnP configuration endpoint. 4. Employ network segmentation to isolate vulnerable routers from critical enterprise systems and sensitive data. 5. Monitor network traffic for unusual or malformed requests targeting the /goform/SetUpnpCfg endpoint or other router management interfaces. 6. Use intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect exploitation attempts. 7. Educate IT staff and users about the risks of using consumer-grade routers in enterprise environments and encourage deployment of enterprise-grade network equipment with robust security features. 8. Maintain an inventory of all network devices to identify and prioritize remediation of vulnerable Tenda AC7 routers. 9. Consider implementing VPNs or other secure remote access methods to reduce exposure of router management interfaces to the internet.