CVE-2022-36158 is a high-severity vulnerability affecting Contec FXA3200 devices running firmware version 1.13.00 and earlier. The vulnerability stems from insecure permissions configured in the Wireless LAN Manager interface, specifically through a hidden web page located at /usr/www/ja/mnt_cmd.cgi. This page allows unauthenticated remote attackers to execute arbitrary Linux commands with root privileges. The vulnerability is classified under CWE-425 (Direct Request ('Forced Browsing')), indicating that the hidden page is accessible without proper access controls or authentication checks. The CVSS 3.1 base score is 8.8, reflecting a high impact on confidentiality, integrity, and availability, with no privileges or user interaction required, and remote access possible over the network. Exploitation involves sending crafted requests to the hidden CGI endpoint, which executes commands as the root user, potentially allowing full system compromise, data exfiltration, or disruption of device functionality. No known exploits in the wild have been reported yet, and no official patches or vendor advisories are currently available. The vulnerability affects embedded Linux-based network devices, likely used in industrial or enterprise environments for wireless LAN management.

For European organizations, this vulnerability poses a significant risk, especially for those deploying Contec FXA3200 devices in critical infrastructure, manufacturing, or enterprise wireless networks. Successful exploitation can lead to complete device takeover, enabling attackers to manipulate network configurations, intercept or disrupt wireless communications, and pivot to internal networks. Confidentiality is at risk due to potential data leakage, integrity is compromised by unauthorized command execution, and availability can be impacted by device disruption or denial of service. Given the root-level access, attackers could also install persistent backdoors or malware, increasing long-term risk. The lack of authentication and user interaction requirements means that attackers can exploit the vulnerability remotely and stealthily. European organizations relying on these devices without compensating controls may face operational disruptions, regulatory compliance issues (e.g., GDPR breaches), and reputational damage.

Immediate mitigation steps include isolating affected Contec FXA3200 devices from untrusted networks to prevent remote exploitation. Network segmentation should be enforced to limit access to management interfaces. Organizations should conduct thorough inventories to identify all affected devices. Since no official patches are currently available, applying compensating controls such as firewall rules blocking access to the /usr/www/ja/mnt_cmd.cgi endpoint and disabling unused web management interfaces is critical. Monitoring network traffic for suspicious requests targeting this CGI path can help detect exploitation attempts. Implementing strict access controls, including VPN or jump hosts for management access, can reduce exposure. Organizations should engage with Contec or authorized vendors to obtain firmware updates or security advisories. Additionally, consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting this vulnerability. Finally, prepare incident response plans to quickly address potential compromises.