CVE-2022-44156 is a high-severity vulnerability identified in the firmware version V15.03.05.19 of the Tenda AC15 router. The vulnerability is a buffer overflow occurring in the function formSetIpMacBind. Buffer overflow vulnerabilities arise when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory, which can lead to unpredictable behavior including crashes or execution of arbitrary code. In this case, the vulnerability allows an unauthenticated remote attacker to send specially crafted network packets to the router, triggering the overflow without requiring any user interaction or prior authentication. The CVSS 3.1 base score of 7.5 reflects a network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but a high impact on availability (A:H). This means the primary consequence is denial of service, potentially causing the router to crash or reboot, disrupting network connectivity. The vulnerability is classified under CWE-787 (Out-of-bounds Write), a common and critical class of memory corruption bugs. No public exploits or patches have been reported as of the publication date (November 21, 2022), but the presence of a buffer overflow in a widely deployed consumer router model poses a significant risk if exploited. The lack of vendor and product metadata in the provided information limits detailed attribution, but the Tenda AC15 is a known consumer-grade Wi-Fi router model widely used in various regions including Europe. The vulnerability could be exploited remotely over the network, making it a serious threat to affected devices exposed to untrusted networks or the internet.

For European organizations, the impact of this vulnerability primarily concerns network availability and stability. The Tenda AC15 router is commonly used in small and medium-sized enterprises (SMEs) and residential environments, which may serve as entry points or network infrastructure components. Exploitation could lead to denial of service conditions, causing network outages, loss of internet connectivity, and disruption of business operations. While the vulnerability does not directly compromise confidentiality or integrity, the resulting downtime could affect critical services, remote work capabilities, and communications. Additionally, persistent denial of service could be leveraged as part of larger multi-stage attacks or to facilitate lateral movement within networks. Organizations relying on these routers without proper segmentation or monitoring may face increased risk. The absence of known exploits in the wild reduces immediate threat but does not eliminate the risk, especially as attackers often develop exploits post-disclosure. The impact is more pronounced for organizations with limited IT resources or those using consumer-grade equipment in critical roles. Given the network-based attack vector and no authentication requirement, attackers can attempt exploitation remotely, increasing the threat surface for exposed devices.

Identify all Tenda AC15 routers running firmware version V15.03.05.19 within the network through asset inventory and network scanning. Restrict remote management access to the router by disabling WAN-side administration interfaces or limiting access via firewall rules to trusted IP addresses only. Isolate affected routers from untrusted networks, especially the internet, by placing them behind additional security layers such as firewalls or VPN gateways. Monitor network traffic for unusual or malformed packets targeting the formSetIpMacBind function or related router services, using IDS/IPS solutions with custom signatures if possible. Engage with Tenda support channels or official firmware repositories to obtain and apply any available patches or firmware updates addressing this vulnerability as soon as they are released. If patching is not immediately possible, consider replacing vulnerable devices with models from vendors with timely security updates and better enterprise support. Implement network segmentation to limit the impact of potential router failures on critical infrastructure and sensitive data environments. Educate IT staff and end-users about the risks of using consumer-grade routers in enterprise environments and encourage best practices for device management and network security.