CVE-2025-12233 identifies a buffer overflow vulnerability in the Tenda CH22 router firmware version 1.0.0.1. The vulnerability resides in the fromSafeUrlFilter function, specifically in the /goform/SafeUrlFilter endpoint, which processes the 'page' argument. Improper handling of this argument allows an attacker to overflow a buffer, potentially overwriting adjacent memory. This flaw can be triggered remotely over the network without requiring authentication or user interaction, making it highly exploitable. The buffer overflow can lead to arbitrary code execution or denial of service, compromising the device's confidentiality, integrity, and availability. The CVSS 4.0 score of 8.7 reflects the high impact and ease of exploitation, with low attack complexity and no privileges or user interaction needed. While no active exploitation has been reported, a public exploit is available, increasing the urgency for mitigation. The vulnerability affects a specific firmware version (1.0.0.1), so devices running this version or earlier are at risk. The lack of official patches at the time of publication necessitates interim protective measures. Given that Tenda CH22 devices are commonly deployed in small to medium enterprise and home networks, the vulnerability poses a significant threat to network security and operational continuity.

For European organizations, this vulnerability presents a critical risk to network infrastructure security. Exploitation could allow attackers to gain control over affected routers, enabling interception or manipulation of network traffic, lateral movement within networks, or disruption of services. This is particularly concerning for sectors relying on Tenda CH22 devices for internet connectivity or internal networking, including SMEs, educational institutions, and possibly some public sector entities. The compromise of these devices could lead to data breaches, loss of service availability, and damage to organizational reputation. Additionally, attackers could leverage compromised routers as footholds for broader attacks against corporate or governmental networks. The remote, unauthenticated nature of the exploit increases the likelihood of widespread attacks, especially if automated scanning and exploitation tools emerge following the public exploit release.

1. Immediate action should be taken to identify all Tenda CH22 devices running firmware version 1.0.0.1 within the network. 2. Monitor Tenda's official channels for firmware updates or patches addressing CVE-2025-12233 and apply them promptly once available. 3. Until patches are released, restrict access to the /goform/SafeUrlFilter endpoint by implementing network-level controls such as firewall rules or access control lists limiting management interface exposure to trusted IP addresses only. 4. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts targeting this vulnerability. 5. Conduct network segmentation to isolate vulnerable devices from critical assets, reducing potential lateral movement. 6. Regularly audit router configurations and logs for unusual activity indicative of exploitation attempts. 7. Educate IT staff about the vulnerability and encourage vigilance for signs of compromise. 8. Consider replacing vulnerable devices with models from vendors with stronger security track records if patching is delayed or unavailable.