CVE-2025-12232 is a buffer overflow vulnerability identified in the Tenda CH22 router firmware version 1.0.0.1. The vulnerability resides in the fromSafeClientFilter function, specifically in the handling of the 'page' argument within the /goform/SafeClientFilter endpoint. Improper validation or sanitization of this input allows an attacker to overflow a buffer, which can lead to arbitrary code execution. The attack vector is remote network access, requiring no authentication or user interaction, making it highly exploitable. The vulnerability affects the core firmware component responsible for client filtering, which is critical for network security and access control. The CVSS 4.0 score of 8.7 indicates a high-severity issue with low attack complexity and no privileges required. Although no known exploits are currently active in the wild, the public availability of exploit code significantly raises the risk of exploitation. The vulnerability can compromise confidentiality, integrity, and availability of affected devices, potentially allowing attackers to take control of the router, intercept or manipulate network traffic, and disrupt network operations. The lack of available patches at the time of disclosure necessitates immediate mitigation efforts by users and administrators.

For European organizations, this vulnerability poses a significant risk to network infrastructure security. Tenda CH22 routers are often deployed in small to medium enterprise environments and possibly in some critical infrastructure segments. Exploitation could lead to full device compromise, enabling attackers to intercept sensitive communications, inject malicious traffic, or pivot into internal networks. This could result in data breaches, service disruptions, or facilitate further attacks such as ransomware or espionage. The remote, unauthenticated nature of the exploit increases the attack surface, especially for organizations with exposed management interfaces or insufficient network segmentation. Given the high CVSS score and public exploit availability, the threat to confidentiality, integrity, and availability is substantial. European organizations relying on Tenda CH22 devices must consider this vulnerability a critical security concern, particularly those in sectors like finance, healthcare, government, and telecommunications where network reliability and data protection are paramount.

1. Immediate network segmentation: Isolate Tenda CH22 devices from critical network segments and restrict access to management interfaces to trusted IPs only. 2. Disable remote management interfaces if not strictly necessary to reduce exposure. 3. Monitor network traffic for unusual activity targeting /goform/SafeClientFilter or anomalous requests containing crafted 'page' parameters. 4. Implement Web Application Firewall (WAF) or Intrusion Prevention Systems (IPS) rules to detect and block exploit attempts targeting this vulnerability. 5. Engage with Tenda support or vendor channels to obtain firmware updates or patches as soon as they become available. 6. If patching is not immediately possible, consider temporary device replacement or use of alternative secure routing solutions. 7. Conduct thorough audits of all Tenda CH22 devices in the environment to identify affected versions and prioritize remediation. 8. Educate network administrators about the vulnerability and ensure incident response plans include steps for potential exploitation scenarios. 9. Apply network-level access controls such as VPNs and multi-factor authentication for device management to add layers of defense.