CVE-2025-14993 is a stack-based buffer overflow vulnerability identified in the Tenda AC18 router firmware version 15.03.05.05. The vulnerability resides in the HTTP request handler component, specifically within the /goform/SetDlnaCfg endpoint. The flaw arises from improper handling of the scanList argument passed to the sprintf function, which does not adequately validate input length, leading to a stack overflow condition. This memory corruption can be exploited remotely by sending a crafted HTTP request to the affected endpoint, without requiring authentication or user interaction. Successful exploitation can result in arbitrary code execution with elevated privileges on the device, potentially allowing attackers to take full control of the router. The vulnerability has been assigned a CVSS 4.0 score of 8.7, reflecting its high impact and low attack complexity. Although no confirmed active exploitation in the wild has been reported, the public availability of exploit code increases the risk of imminent attacks. The Tenda AC18 is commonly deployed in consumer and small business environments, making it a valuable target for attackers seeking to compromise network gateways, intercept traffic, or pivot to internal networks. The vulnerability's exploitation could lead to confidentiality breaches, integrity violations, and denial of service conditions. Due to the critical role routers play in network security, this vulnerability poses a significant threat to affected organizations.

For European organizations, exploitation of CVE-2025-14993 could lead to severe consequences including unauthorized access to internal networks, interception and manipulation of sensitive data, and disruption of network availability. Compromise of the Tenda AC18 router could allow attackers to bypass perimeter defenses, deploy malware, or establish persistent footholds within corporate or home networks. This is particularly concerning for SMEs and remote workers who rely on such consumer-grade routers without additional security layers. The vulnerability undermines the confidentiality, integrity, and availability of network communications. Given the remote exploitation capability without authentication, attackers can target vulnerable devices at scale, potentially leading to widespread network outages or data breaches. The lack of official patches at the time of disclosure further exacerbates the risk, forcing organizations to rely on interim mitigations. The impact extends beyond individual devices to the broader network infrastructure, potentially affecting critical business operations and compliance with data protection regulations such as GDPR.

1. Monitor Tenda's official channels for firmware updates addressing CVE-2025-14993 and apply patches immediately upon release. 2. Until patches are available, disable the DLNA service or the /goform/SetDlnaCfg endpoint if possible to eliminate the attack surface. 3. Implement network segmentation to isolate vulnerable routers from critical internal systems, limiting lateral movement in case of compromise. 4. Deploy intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to detect and block malicious HTTP requests targeting the vulnerable endpoint. 5. Restrict remote management access to the router by disabling WAN-side administration or limiting it to trusted IP addresses. 6. Conduct regular network traffic analysis to identify anomalous patterns indicative of exploitation attempts. 7. Educate users about the risks of using outdated router firmware and encourage secure configuration practices. 8. Consider replacing vulnerable Tenda AC18 devices with models from vendors with stronger security track records if patching is delayed or unsupported.