CVE-2022-45658 is a high-severity buffer overflow vulnerability identified in the firmware of the Tenda AC6V1.0 wireless router, specifically version V15.03.05.19. The flaw exists in the setSchedWifi function, which processes the schedEndTime parameter. A buffer overflow occurs when this parameter is improperly handled, allowing an attacker to overwrite memory beyond the intended buffer boundaries. This type of vulnerability is classified under CWE-120, which pertains to classic buffer overflow issues that can lead to arbitrary code execution or denial of service. The vulnerability has a CVSS v3.1 base score of 7.5, indicating a high impact primarily on availability (A:H) with no impact on confidentiality or integrity. The attack vector is network-based (AV:N), requiring no privileges (PR:N) and no user interaction (UI:N), making it remotely exploitable by unauthenticated attackers. The scope is unchanged (S:U), meaning the vulnerability affects only the vulnerable component without impacting other system components. Although no known exploits have been reported in the wild, the nature of the vulnerability and its ease of exploitation make it a significant risk for affected devices. The lack of vendor or product details beyond the Tenda AC6V1.0 router model limits the breadth of affected devices but confirms the issue is firmware-specific. The absence of available patches at the time of reporting increases the urgency for mitigation and monitoring.

For European organizations, this vulnerability poses a significant risk to network infrastructure relying on Tenda AC6V1.0 routers, which are commonly used in small to medium-sized enterprises and residential environments. Exploitation could lead to denial of service conditions, disrupting internet connectivity and internal network communications, which can halt business operations and impact productivity. Although the vulnerability does not directly compromise confidentiality or integrity, the resulting service outages could affect critical business functions, especially for organizations with remote or distributed workforces. Additionally, compromised routers could serve as footholds for further network attacks or be leveraged in botnet activities, indirectly threatening broader organizational security. The impact is more pronounced in sectors where network availability is critical, such as finance, healthcare, and manufacturing. Given the remote exploitability without authentication or user interaction, attackers could scan for vulnerable devices across European networks, increasing the likelihood of widespread disruption if not mitigated promptly.

1. Immediate network inventory and identification of all Tenda AC6V1.0 routers running firmware version V15.03.05.19 within the organization. 2. Isolate vulnerable devices from critical network segments to limit potential impact. 3. Monitor network traffic for unusual patterns or repeated attempts to access the setSchedWifi function, which may indicate exploitation attempts. 4. Implement network-level access controls such as firewall rules to restrict external access to router management interfaces and related services. 5. Engage with Tenda support channels to obtain firmware updates or patches addressing this vulnerability; if unavailable, consider temporary replacement of affected devices with models from vendors providing timely security updates. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics targeting buffer overflow attempts on router management interfaces. 7. Educate IT staff on the specific vulnerability to ensure rapid response to any signs of exploitation. 8. Regularly review and update router firmware as new patches become available to maintain security posture.