CVE-2025-14993 identifies a critical stack-based buffer overflow vulnerability in the Tenda AC18 router firmware version 15.03.05.05. The vulnerability arises from improper handling of the scanList parameter passed to the sprintf function in the /goform/SetDlnaCfg HTTP endpoint, part of the device's HTTP request handler. Because sprintf does not perform bounds checking, a specially crafted scanList argument can overflow the stack buffer, corrupting adjacent memory. This flaw is remotely exploitable over the network without requiring authentication or user interaction, making it highly accessible to attackers. Successful exploitation can lead to arbitrary code execution with elevated privileges, enabling attackers to take full control of the device, disrupt network operations, or pivot into internal networks. The vulnerability has a CVSS 4.0 base score of 8.7, reflecting its high impact on confidentiality, integrity, and availability. Although no confirmed exploits in the wild are reported, a public exploit is available, increasing the likelihood of active exploitation. The affected product, Tenda AC18, is a widely used consumer and small business router, making this vulnerability relevant to a broad user base. The lack of available patches at the time of disclosure necessitates immediate mitigation efforts to reduce exposure.

The impact of CVE-2025-14993 is significant for organizations and individuals using Tenda AC18 routers. Exploitation can lead to complete compromise of the affected device, allowing attackers to execute arbitrary code remotely. This can result in unauthorized access to internal networks, interception or manipulation of network traffic, disruption of network services, and potential lateral movement to other connected systems. The vulnerability threatens confidentiality by exposing sensitive data, integrity by allowing unauthorized changes, and availability by causing device crashes or network outages. Given the router's role as a network gateway, compromised devices can serve as persistent footholds for attackers, facilitating further attacks on organizational infrastructure. The public availability of an exploit increases the risk of widespread attacks, including automated scanning and exploitation campaigns. Organizations relying on Tenda AC18 devices in home offices, small businesses, or branch locations face elevated risks, especially if devices are exposed to the internet without adequate network segmentation or firewall protections.

To mitigate CVE-2025-14993, organizations should first check for and apply any official firmware updates or patches released by Tenda addressing this vulnerability. In the absence of patches, network administrators should restrict access to the router's management interfaces by implementing firewall rules that block inbound traffic to the /goform/SetDlnaCfg endpoint or the HTTP management interface from untrusted networks, especially the internet. Disabling remote management features or restricting them to trusted IP addresses can reduce exposure. Network segmentation should be employed to isolate vulnerable devices from critical infrastructure. Monitoring network traffic for unusual requests targeting the scanList parameter or the affected endpoint can help detect exploitation attempts. Additionally, organizations should consider replacing affected devices with models from vendors with more robust security track records if timely patching is not feasible. Regularly updating router firmware and maintaining an inventory of network devices will aid in managing such vulnerabilities proactively.