CVE-2025-12235 is a buffer overflow vulnerability identified in the Tenda CH22 router firmware version 1.0.0.1. The flaw exists in the fromSetIpBind function within the /goform/SetIpBind endpoint, where improper handling of the 'page' argument allows an attacker to overflow a buffer. This vulnerability requires the attacker to be on the local network (AV:A) and possess low privileges (PR:L), but does not require user interaction (UI:N) or authentication (AT:N). The buffer overflow can lead to arbitrary code execution or denial of service, severely impacting the device's confidentiality, integrity, and availability. The CVSS 4.0 score of 8.6 reflects the high impact and relatively low attack complexity. Although no exploits have been observed in the wild, a public exploit is available, increasing the likelihood of exploitation. The vulnerability affects only version 1.0.0.1 of the firmware, and no official patch has been released yet. The attack surface is limited to local network access, which means attackers must have network proximity or compromise a device within the network to exploit this vulnerability. The Tenda CH22 is a consumer and small business router, often deployed in home and small office environments, which may be part of larger organizational networks in Europe. The vulnerability's exploitation could allow attackers to gain control over the router, manipulate network traffic, intercept sensitive data, or disrupt network services.

For European organizations, exploitation of CVE-2025-12235 could lead to significant security breaches. Compromise of Tenda CH22 routers may allow attackers to intercept or manipulate internal network traffic, leading to data leakage or man-in-the-middle attacks. Integrity of network configurations could be altered, causing network disruptions or persistent backdoors. Availability could be impacted through denial-of-service conditions triggered by the overflow. Given the router's role as a network gateway, attackers could pivot to other internal systems, escalating the breach's scope. Organizations relying on Tenda CH22 devices in critical infrastructure or sensitive environments face increased risk. The requirement for local network access limits remote exploitation but does not eliminate risk, especially in environments with weak internal network segmentation or compromised endpoints. European entities with distributed offices or remote workers connected via these routers may see increased exposure. The public availability of an exploit raises the urgency for mitigation to prevent opportunistic attacks.

1. Immediately restrict physical and network access to local networks containing Tenda CH22 devices to trusted personnel only. 2. Implement strict network segmentation to isolate vulnerable routers from sensitive systems and limit lateral movement. 3. Monitor network traffic for unusual activity targeting /goform/SetIpBind or anomalous requests with suspicious 'page' parameters. 4. Disable or restrict access to the vulnerable endpoint if possible via router configuration or firewall rules. 5. Regularly audit and inventory network devices to identify all Tenda CH22 routers running vulnerable firmware version 1.0.0.1. 6. Engage with Tenda for firmware updates or security patches and apply them promptly once available. 7. Consider replacing vulnerable devices with models from vendors with stronger security track records if patching is delayed. 8. Educate internal users about the risks of connecting untrusted devices to local networks. 9. Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts targeting this vulnerability. 10. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.