CVE-2022-45655 is a high-severity buffer overflow vulnerability identified in the Tenda AC6V1.0 router firmware version 15.03.05.19. The flaw exists in the function form_fast_setting_wifi_set, specifically triggered via the timeZone parameter. Buffer overflow vulnerabilities, categorized 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 timeZone parameter input allows an attacker to overflow the buffer, which can lead to denial of service (DoS) conditions by crashing the device or, in some cases, arbitrary code execution if the overflow is exploited to manipulate the control flow. The CVSS 3.1 base score of 7.5 indicates a high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and impact limited to availability (A:H) without affecting confidentiality or integrity. This means an unauthenticated remote attacker can exploit this vulnerability over the network without user interaction to cause a complete denial of service on the affected device. No patches or known exploits in the wild have been reported as of the publication date (December 2, 2022). The vulnerability is enriched by CISA, indicating recognition by US cybersecurity authorities. The lack of vendor or product details beyond the Tenda AC6V1.0 router firmware version limits the scope of affected products, but the vulnerability is specific to this firmware version. Given the nature of consumer-grade routers, exploitation could disrupt home or small office network availability, potentially impacting connected devices and services reliant on continuous network access.

For European organizations, the primary impact of CVE-2022-45655 is the potential disruption of network availability due to denial of service on affected Tenda AC6 routers. Organizations relying on these routers for internet connectivity or internal network routing could experience outages, leading to operational downtime, loss of productivity, and potential interruption of critical services. While the vulnerability does not directly compromise confidentiality or integrity, the loss of availability can indirectly affect business continuity, especially for small and medium enterprises (SMEs) or remote offices that may use consumer-grade networking equipment. Additionally, if exploited at scale, such vulnerabilities could be leveraged in larger denial-of-service campaigns or as part of botnet recruitment, further amplifying the impact. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits over time. European organizations with limited IT security resources or those that do not regularly update firmware may be particularly vulnerable. The impact is more pronounced in sectors where network uptime is critical, such as healthcare, finance, and public administration.

1. Firmware Update: Although no official patch links are provided, organizations and users should monitor Tenda’s official channels for firmware updates addressing this vulnerability and apply them promptly once available. 2. Network Segmentation: Isolate vulnerable Tenda AC6 routers from critical network segments to limit the impact of potential denial of service. 3. Access Controls: Restrict remote management access to the router’s administrative interface by disabling WAN-side management or limiting access to trusted IP addresses only. 4. Intrusion Detection: Deploy network intrusion detection systems (NIDS) to monitor for anomalous traffic patterns targeting the timeZone parameter or unusual requests to the router’s configuration endpoints. 5. Device Replacement: For critical environments, consider replacing vulnerable Tenda AC6 routers with enterprise-grade devices that receive regular security updates and have robust security features. 6. User Awareness: Educate users about the importance of not exposing router management interfaces to the internet and the risks of using outdated firmware. 7. Network Monitoring: Continuously monitor network performance and availability to quickly detect and respond to denial of service incidents potentially linked to this vulnerability.