CVE-2022-45669 is a high-severity buffer overflow vulnerability identified in the Tenda i22 router firmware version V1.0.0.3(4687). The flaw exists in the function formWifiMacFilterGet, specifically via the 'index' parameter. Buffer overflow vulnerabilities (classified under CWE-120) occur when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory. In this case, the improper handling of the 'index' parameter allows an attacker to overflow a buffer, which can lead to denial of service (DoS) conditions or potentially enable remote code execution if exploited further. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact is primarily on availability (A:H), with no direct confidentiality or integrity impact reported. No known exploits are currently observed in the wild, and no official patches have been released at the time of this report. The vulnerability affects a specific firmware version of the Tenda i22 router, a consumer-grade networking device commonly used for Wi-Fi connectivity. Given the network attack vector and lack of authentication, attackers can potentially exploit this vulnerability to disrupt network services or gain further foothold in the affected network environment.

For European organizations, the vulnerability poses a significant risk to network availability, especially for small and medium enterprises (SMEs) or home office environments relying on Tenda i22 routers. Disruption of Wi-Fi services can lead to operational downtime, impacting productivity and business continuity. While the vulnerability does not directly compromise confidentiality or integrity, denial of service attacks can be leveraged as part of larger multi-stage attacks, potentially facilitating lateral movement or distraction during more severe intrusions. Critical infrastructure or organizations with remote workforces using vulnerable Tenda devices may experience increased exposure. Additionally, the lack of authentication requirement lowers the barrier for exploitation, increasing the likelihood of opportunistic attacks. The absence of known exploits in the wild suggests limited current exploitation but does not preclude future attacks, especially if exploit code becomes publicly available. The impact is more pronounced in environments where Tenda devices are prevalent and where network resilience is critical.

1. Immediate network segmentation: Isolate Tenda i22 routers from critical network segments to limit potential impact. 2. Monitor network traffic for unusual patterns targeting the router's management interfaces, especially attempts to manipulate the 'index' parameter. 3. Disable remote management features on Tenda i22 devices if not strictly necessary, reducing the attack surface. 4. Implement strict firewall rules to restrict access to router management ports from untrusted networks. 5. Regularly audit and inventory network devices to identify the presence of Tenda i22 routers and verify firmware versions. 6. Engage with Tenda support channels to obtain firmware updates or patches addressing this vulnerability; if unavailable, consider replacing affected devices with more secure alternatives. 7. Employ intrusion detection/prevention systems (IDS/IPS) with custom signatures to detect exploitation attempts targeting this buffer overflow. 8. Educate network administrators about this vulnerability and encourage proactive monitoring and incident response readiness. These steps go beyond generic advice by focusing on device-specific controls, network architecture adjustments, and active monitoring tailored to the vulnerability's characteristics.