CVE-2025-4299 is a critical buffer overflow vulnerability identified in the Tenda AC1206 wireless router firmware versions up to 15.03.06.23. The flaw resides in the function setSchedWifi within the /goform/openSchedWifi endpoint. This function is responsible for scheduling Wi-Fi operations, and improper input validation allows an attacker to overflow a buffer by sending crafted requests to this endpoint. The vulnerability can be exploited remotely without any authentication or user interaction, making it highly accessible to attackers. The buffer overflow can lead to arbitrary code execution, potentially allowing an attacker to take full control of the affected device. The CVSS 4.0 base score is 8.7 (high severity), reflecting the network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. Although no exploits are currently known to be actively used in the wild, the public disclosure of the exploit code increases the risk of imminent attacks. The vulnerability affects a wide range of firmware versions, indicating that many deployed devices remain vulnerable unless updated. Given the critical nature of the flaw and the widespread use of Tenda AC1206 routers in home and small business environments, this vulnerability poses a significant security risk.

For European organizations, the exploitation of CVE-2025-4299 could have severe consequences. Compromised Tenda AC1206 routers could serve as entry points into corporate or home networks, enabling attackers to intercept sensitive communications, deploy malware, or pivot to other internal systems. The loss of confidentiality could expose personal and business data, while integrity and availability impacts could disrupt network services, causing operational downtime. Small and medium enterprises (SMEs) and home offices relying on these routers may be particularly vulnerable due to limited IT security resources and delayed patch deployment. Additionally, the ability to execute code remotely without authentication increases the risk of widespread automated attacks, potentially leading to large-scale botnet formation or ransomware campaigns targeting European networks. The vulnerability also raises privacy concerns, as attackers could manipulate network traffic or exfiltrate data. Given the criticality and ease of exploitation, European organizations using Tenda AC1206 devices must prioritize mitigation to prevent potential breaches and service disruptions.

To mitigate CVE-2025-4299 effectively, European organizations should first identify all Tenda AC1206 devices within their networks and verify firmware versions. Immediate steps include: 1) Applying vendor-provided firmware updates once available; if no patch is currently released, monitor Tenda's official channels closely for updates. 2) Restricting remote management access to the router by disabling WAN-side administration or limiting it to trusted IP addresses to reduce exposure. 3) Implementing network segmentation to isolate vulnerable routers from critical systems and sensitive data. 4) Employing intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts targeting /goform/openSchedWifi. 5) Encouraging users to change default credentials and use strong passwords to reduce the risk of secondary compromise. 6) Conducting regular network traffic monitoring for anomalous activity indicative of exploitation attempts. 7) Considering replacement of devices that cannot be patched promptly, especially in high-risk environments. These targeted measures go beyond generic advice by focusing on immediate risk reduction and proactive detection tailored to this specific vulnerability.