CVE-2025-11528 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 within the /goform/saveAutoQos endpoint, which processes the 'enable' argument. Improper handling of this argument allows an attacker to overflow the stack buffer, potentially overwriting return addresses or other control data. This flaw enables remote code execution without requiring authentication or user interaction, making it highly exploitable over the network. The vulnerability has a CVSS 4.0 score of 8.7, indicating high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:L), and no user interaction (UI:N). The vulnerability impacts confidentiality, integrity, and availability, as an attacker could execute arbitrary code, disrupt device operation, or intercept network traffic. Although no known exploits are currently active in the wild, a public exploit exists, increasing the likelihood of exploitation. The lack of available patches at the time of publication necessitates immediate mitigation efforts. The Tenda AC7 is a widely used consumer-grade router, often deployed in home and small office environments, making this vulnerability a significant risk for end users and small businesses relying on this hardware for network connectivity and security.

The impact of CVE-2025-11528 is substantial for organizations and individuals using the Tenda AC7 router. Successful exploitation allows remote attackers to execute arbitrary code on the device, potentially gaining full control over the router. This can lead to interception or manipulation of network traffic, unauthorized access to internal networks, disruption of internet connectivity, and use of the compromised device as a foothold for further attacks. The vulnerability threatens confidentiality by enabling data interception, integrity by allowing modification of network traffic or device configuration, and availability by causing device crashes or denial of service. Small businesses and home users are particularly vulnerable due to the common use of Tenda AC7 routers in these environments, which often lack robust network defenses. The availability of a public exploit increases the risk of widespread attacks, especially in regions where Tenda devices are prevalent. The lack of authentication and user interaction requirements lowers the barrier for attackers, potentially enabling automated exploitation campaigns. Overall, this vulnerability poses a critical risk to network security and privacy for affected users worldwide.

1. Immediate mitigation should focus on isolating the Tenda AC7 devices from untrusted networks, especially the internet, by placing them behind firewalls or VPNs to restrict access to the /goform/saveAutoQos endpoint. 2. Disable or restrict remote management features on the router to prevent external access to vulnerable interfaces. 3. Monitor network traffic for unusual requests targeting the /goform/saveAutoQos path or anomalous behavior indicative of exploitation attempts. 4. If possible, apply any vendor-provided firmware updates or patches as soon as they become available; if no patch exists, consider replacing the device with a more secure alternative. 5. Implement network segmentation to limit the impact of a compromised router on critical internal systems. 6. Use intrusion detection/prevention systems (IDS/IPS) configured to detect exploitation attempts targeting this vulnerability. 7. Educate users about the risks of using outdated firmware and the importance of regular updates. 8. Maintain backups of router configurations and network settings to facilitate rapid recovery if compromise occurs.