CVE-2025-11389 is a stack-based buffer overflow vulnerability identified in the Tenda AC15 router firmware version 15.03.05.18. The vulnerability resides in an unspecified function related to the /goform/saveAutoQos endpoint, where the 'enable' parameter is improperly handled, leading to a stack overflow condition. This flaw can be exploited remotely without requiring authentication or user interaction, allowing attackers to execute arbitrary code on the device. The vulnerability affects the device's QoS configuration interface, which is typically accessible via the router's web management interface or potentially exposed services. The buffer overflow can corrupt the stack, enabling control over the program execution flow, which attackers can leverage to deploy malware, disrupt network services, or pivot into internal networks. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no active exploitation has been reported, the public release of an exploit increases the likelihood of imminent attacks. The absence of official patches at the time of publication necessitates immediate defensive measures to reduce exposure.

The vulnerability poses a significant risk to organizations relying on Tenda AC15 routers, as successful exploitation can lead to full compromise of the device. Attackers can execute arbitrary code remotely, potentially gaining control over the router's firmware and network traffic. This can result in interception or manipulation of sensitive data, disruption of network availability, and use of the compromised device as a foothold for further attacks within the internal network. The integrity of network configurations can be altered, leading to persistent backdoors or denial of service conditions. Given the router's role as a network gateway, the impact extends beyond the device itself, threatening the confidentiality and availability of connected systems. The exploitability without authentication and user interaction makes this vulnerability particularly dangerous, increasing the attack surface and likelihood of automated exploitation campaigns. Organizations with limited network segmentation or outdated firmware are at heightened risk.

1. Immediately verify the firmware version of all Tenda AC15 devices and avoid using version 15.03.05.18 until a patch is released. 2. Monitor Tenda's official channels for firmware updates addressing this vulnerability and apply patches promptly once available. 3. Restrict access to the router's management interfaces by implementing network segmentation and firewall rules to limit exposure to trusted IP addresses only. 4. Disable remote management features if not required, especially web-based configuration portals accessible from the internet. 5. Employ network intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts targeting /goform/saveAutoQos or anomalous buffer overflow patterns. 6. Conduct regular network traffic monitoring for unusual activity originating from or targeting Tenda AC15 devices. 7. Consider temporary replacement or isolation of vulnerable devices in high-security environments until remediation is confirmed. 8. Educate network administrators about the risks and signs of exploitation related to this vulnerability to enable rapid incident response.