CVE-2022-45957 is a high-severity vulnerability identified in the ZTE ZXHN-H108NS router, specifically affecting devices running firmware version H108NSV1.0.7u_ZRD_GR2_A68. The vulnerability is a remote stack-based buffer overflow (CWE-787), which allows an unauthenticated attacker to send specially crafted network packets to the router and trigger a buffer overflow condition. This overflow can lead to denial of service (DoS) by crashing the device or potentially enable remote code execution, depending on the exploitability of the overflow. The CVSS 3.1 base score of 7.5 reflects the fact that the vulnerability can be exploited remotely over the network without any privileges or user interaction, and it impacts the availability of the device (A:H) but does not directly affect confidentiality or integrity. The lack of vendor or product details beyond the router model and firmware version suggests limited public information on the exact attack vector or exploit code. No patches or mitigations have been officially published, and there are no known exploits in the wild at this time. However, given the nature of the vulnerability and the critical role of routers in network infrastructure, exploitation could disrupt internet connectivity or be leveraged as a foothold for further network compromise.

For European organizations, this vulnerability poses a significant risk to network availability and operational continuity. The ZTE ZXHN-H108NS router is commonly deployed by some ISPs and enterprises for broadband access, especially in residential and small office environments. Successful exploitation could lead to widespread denial of service, interrupting internet access and internal network communications. This disruption could affect remote work, cloud service access, and critical business operations. Additionally, if attackers manage to escalate the impact beyond DoS to remote code execution, they could pivot into internal networks, potentially compromising sensitive data or infrastructure. The impact is particularly concerning for sectors reliant on stable internet connectivity such as finance, healthcare, and manufacturing. Moreover, the absence of patches increases the window of exposure, and the ease of exploitation (no authentication or user interaction required) heightens the threat level. European organizations using this router model or supplied by ISPs deploying it are at risk of service outages and potential security breaches.

Given the absence of official patches, organizations should first identify if they are using the ZTE ZXHN-H108NS router with the affected firmware version. Network administrators should consider the following specific mitigations: 1) Replace or upgrade affected routers to models with updated firmware or from alternative vendors with active security support. 2) If replacement is not immediately feasible, isolate the vulnerable routers behind additional security layers such as firewalls or intrusion prevention systems that can detect and block anomalous traffic patterns targeting the router's management interfaces. 3) Disable remote management features on the router to reduce exposure to external attacks. 4) Monitor network traffic for unusual activity or repeated malformed packets that could indicate exploitation attempts. 5) Engage with ISPs to confirm if they provide affected devices and request firmware updates or device swaps. 6) Implement network segmentation to limit the impact of a compromised router on critical internal systems. 7) Maintain up-to-date network device inventories and vulnerability scanning to detect similar issues proactively. These steps go beyond generic advice by focusing on device-specific controls and operational practices tailored to this vulnerability.