CVE-2025-11524 is a stack-based buffer overflow vulnerability identified in the Tenda AC7 router firmware version 15.03.06.44. The flaw exists in the processing of the ddnsEn parameter within the /goform/SetDDNSCfg endpoint, which is accessible remotely. By manipulating this argument, an attacker can overflow a stack buffer, potentially overwriting control data such as return addresses or function pointers. This can lead to arbitrary code execution on the device with the privileges of the affected process, which typically runs with elevated rights on the router. The vulnerability requires no authentication or user interaction, making it highly exploitable over the network. The CVSS v4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no prerequisites. Although no active exploitation has been observed in the wild, published proof-of-concept exploits increase the likelihood of imminent attacks. The Tenda AC7 is commonly deployed in consumer and small business environments, where compromised devices could be leveraged for network infiltration, lateral movement, or as part of botnets. The absence of an official patch at the time of disclosure further elevates the risk. Technical mitigation options are limited to network-level controls until firmware updates are released.

For European organizations, the exploitation of CVE-2025-11524 could result in severe consequences. Compromise of Tenda AC7 routers can lead to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network availability. Small and medium enterprises (SMEs) and home office setups relying on these routers are particularly vulnerable due to typically weaker security postures and less frequent patching. Attackers could use compromised routers as footholds to launch further attacks against corporate networks or critical infrastructure. Additionally, the vulnerability could facilitate the creation of large-scale botnets, impacting broader internet stability and service availability. The lack of authentication and remote exploitability means attackers can target devices en masse without user interaction, increasing the scale of potential impact across Europe.

1. Immediately identify and inventory all Tenda AC7 devices running firmware version 15.03.06.44 within the network. 2. Monitor Tenda’s official channels for firmware updates addressing CVE-2025-11524 and apply patches as soon as they become available. 3. Until patches are released, restrict access to the router’s management interfaces by implementing network segmentation and firewall rules to block inbound traffic to the /goform/SetDDNSCfg endpoint. 4. Disable remote management features on affected routers to reduce exposure. 5. Employ network intrusion detection systems (NIDS) to detect anomalous requests targeting the vulnerable endpoint. 6. Educate users and administrators about the risks and signs of compromise related to this vulnerability. 7. Consider replacing vulnerable devices with models from vendors with stronger security track records if patching is delayed or unsupported. 8. Regularly back up router configurations and monitor network traffic for unusual activity indicative of exploitation attempts.