CVE-2022-45656 is a high-severity buffer overflow vulnerability identified in the Tenda AC6 V1.0 router firmware version 15.03.05.19. The flaw exists in the fromSetSysTime function, specifically triggered by the 'time' 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 overflow can be exploited remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability impacts availability (A:H) but does not affect confidentiality or integrity directly. Exploiting this flaw could cause the device to crash or reboot, leading to denial of service conditions. Although no known exploits are currently reported in the wild, the ease of exploitation and network accessibility make it a significant risk. The lack of vendor or product details beyond the Tenda AC6 model limits the scope of affected versions, but the specific firmware version is clearly identified. No patches or mitigation links are currently provided, indicating that affected users must rely on other defensive measures until an official fix is released.

For European organizations, especially those relying on Tenda AC6 routers in their network infrastructure, this vulnerability poses a risk of service disruption due to potential denial of service attacks. The router is typically used in small office/home office (SOHO) environments and possibly in branch offices, meaning that exploitation could interrupt internet connectivity or internal network access. This could affect business continuity, remote work capabilities, and access to cloud services. While the vulnerability does not directly compromise data confidentiality or integrity, the loss of availability can have cascading effects on operational efficiency and incident response. Critical infrastructure sectors or organizations with limited IT support might experience prolonged outages. Additionally, attackers could leverage this vulnerability as part of a larger attack chain, using denial of service as a distraction or to degrade network defenses.

Given the absence of an official patch, European organizations should take immediate steps to mitigate risk: 1) Identify and inventory all Tenda AC6 routers running firmware version 15.03.05.19 within their networks. 2) Restrict remote management access to these devices by disabling WAN-side administration and limiting access to trusted IP addresses only. 3) Implement network segmentation to isolate vulnerable routers from critical systems and sensitive data. 4) Monitor network traffic for unusual patterns or repeated attempts to exploit the 'time' parameter, using intrusion detection systems with custom signatures if possible. 5) Where feasible, replace or upgrade affected devices to models with updated firmware or from vendors with active security support. 6) Engage with Tenda support channels to obtain information on forthcoming patches or firmware updates addressing this vulnerability. 7) Educate IT staff on recognizing symptoms of denial of service attacks related to this flaw and establish incident response procedures to quickly restore affected services.