CVE-2025-11525 is a stack-based buffer overflow vulnerability identified in the Tenda AC7 router firmware version 15.03.06.44. The flaw exists in an unspecified function handling the /goform/SetUpnpCfg endpoint, specifically in the processing of the upnpEn parameter. This parameter manipulation leads to a buffer overflow on the stack, which can be exploited remotely without requiring authentication or user interaction. The vulnerability allows attackers to execute arbitrary code on the device, potentially leading to full compromise of the router. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no need for privileges or user interaction. The vulnerability affects the router’s UPnP configuration interface, a common target due to its network exposure and functionality. While no exploits are currently reported in the wild, the public disclosure increases the likelihood of exploitation attempts. The lack of available patches at the time of disclosure necessitates immediate defensive measures. This vulnerability poses a significant risk to network security, as compromised routers can be used to intercept, manipulate, or disrupt network traffic, and serve as footholds for further attacks within organizational networks.

For European organizations, exploitation of this vulnerability could lead to severe consequences including unauthorized access to internal networks, interception of sensitive data, disruption of network services, and potential lateral movement by attackers. Given the router’s role as a network gateway, compromise could undermine perimeter defenses and facilitate attacks on critical infrastructure or sensitive business systems. The impact is particularly critical for sectors relying on secure and stable network connectivity such as finance, healthcare, government, and telecommunications. Additionally, the vulnerability could be leveraged to create botnets or launch distributed denial-of-service (DDoS) attacks, affecting broader internet stability. The remote and unauthenticated nature of the exploit increases the risk of widespread attacks, especially in environments where Tenda AC7 routers are deployed without adequate network segmentation or monitoring. The absence of a patch at disclosure time further exacerbates the risk, requiring organizations to implement interim protective controls to mitigate potential exploitation.

1. Immediately check for and apply any firmware updates released by Tenda addressing CVE-2025-11525. 2. If patches are not yet available, disable UPnP functionality on the Tenda AC7 routers to prevent exploitation via the vulnerable /goform/SetUpnpCfg endpoint. 3. Restrict access to the router’s management interface to trusted internal IP addresses only, using firewall rules or network segmentation. 4. Monitor network traffic for unusual activity targeting the /goform/SetUpnpCfg endpoint or other suspicious UPnP-related requests. 5. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts against this vulnerability. 6. Conduct regular security audits of network devices to identify and replace vulnerable routers where possible. 7. Educate IT staff about the vulnerability and encourage rapid incident response readiness in case of exploitation attempts. 8. Consider deploying network-level mitigations such as disabling UPnP on upstream devices or isolating vulnerable routers in dedicated network segments to limit exposure.