CVE-2025-12322 is a buffer overflow vulnerability identified in the Tenda CH22 router firmware version 1.0.0.1. The vulnerability resides in the fromNatStaticSetting function, specifically in the handling of the 'page' argument within the /goform/NatStaticSetting endpoint. Improper validation or sanitization of this input allows an attacker to overflow a buffer, potentially overwriting adjacent memory. This flaw can be exploited remotely over the network without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L). The vulnerability impacts confidentiality, integrity, and availability, with high potential for remote code execution or denial of service. The CVSS score of 8.7 (high) reflects the ease of exploitation and the severe consequences. Although no active exploitation has been reported, a public exploit is available, increasing the likelihood of attacks. The vulnerability affects only version 1.0.0.1 of the Tenda CH22 firmware. No official patch links are currently provided, which suggests that users must rely on vendor advisories or implement network-level mitigations. The vulnerability is critical for environments where Tenda CH22 devices are deployed, especially in enterprise or ISP networks, as compromise could lead to network disruption or further lateral attacks.

For European organizations, this vulnerability poses a significant risk to network security and operational continuity. Exploitation could allow attackers to execute arbitrary code on affected routers, potentially gaining control over network traffic, intercepting sensitive data, or launching further attacks within the internal network. The availability of a public exploit increases the risk of widespread attacks, including ransomware or espionage campaigns. Organizations relying on Tenda CH22 devices for critical infrastructure or internet connectivity could face service outages or data breaches. The lack of authentication for exploitation means attackers can target devices exposed to the internet or accessible within internal networks. This could impact sectors such as telecommunications, government, finance, and critical infrastructure providers across Europe. The absence of a vendor patch at the time of disclosure further exacerbates the risk, requiring immediate compensating controls to prevent exploitation.

1. Immediately isolate or restrict network access to Tenda CH22 devices, especially blocking access to the /goform/NatStaticSetting endpoint from untrusted networks. 2. Implement firewall rules or intrusion prevention systems (IPS) to detect and block attempts to exploit the buffer overflow, focusing on malformed requests targeting the 'page' parameter. 3. Monitor network traffic for unusual activity or signs of exploitation attempts related to this vulnerability. 4. Contact Tenda support or check official channels regularly for firmware updates or patches addressing CVE-2025-12322 and apply them promptly once available. 5. If patching is not immediately possible, consider replacing vulnerable devices with alternative hardware from vendors with timely security support. 6. Conduct internal audits to identify all Tenda CH22 devices in the network and assess exposure. 7. Educate network administrators about the vulnerability and ensure incident response plans include this threat scenario. 8. Employ network segmentation to limit the impact of potential compromise of vulnerable devices.