CVE-2024-39762 is an OS command injection vulnerability identified in the Wavlink AC3000 router firmware version M33A8.V5030.210505. The flaw resides in the internet.cgi script's set_add_routing() functionality, where the netmask POST parameter is improperly sanitized, allowing special shell characters to be injected and executed. This improper neutralization of special elements (CWE-77) enables an attacker with authenticated HTTP access to execute arbitrary commands on the underlying operating system. The vulnerability requires authentication but no user interaction beyond that. Exploitation can lead to complete system compromise, including unauthorized disclosure, modification, or destruction of data, and disruption of network services. The CVSS v3.1 score of 9.1 reflects the vulnerability's critical nature, with network attack vector, low attack complexity, high privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. No patches have been publicly released yet, and no known exploits are reported in the wild, but the risk remains high given the severity and ease of exploitation post-authentication.

For European organizations, this vulnerability poses a significant threat to network infrastructure security. The Wavlink AC3000 routers are often deployed in small to medium enterprise and home office environments, where they may serve as primary gateways. Successful exploitation could allow attackers to gain persistent control over these devices, enabling interception or manipulation of network traffic, lateral movement within internal networks, and disruption of critical services. Confidential data could be exfiltrated, and network availability could be severely impacted. Given the critical CVSS score and the potential for full system compromise, organizations relying on these devices face risks including data breaches, operational downtime, and reputational damage. The requirement for authentication limits exposure somewhat but does not eliminate risk, especially if credentials are weak or compromised. The absence of known exploits in the wild currently provides a window for remediation before active attacks emerge.

Organizations should immediately inventory their network to identify any Wavlink AC3000 devices running the affected firmware version M33A8.V5030.210505. Since no official patches are currently available, interim mitigations include restricting administrative access to trusted networks only, enforcing strong authentication mechanisms (complex passwords, multi-factor authentication if supported), and monitoring router logs for suspicious HTTP requests targeting internet.cgi. Network segmentation should be employed to isolate vulnerable devices from critical assets. Additionally, disabling remote management interfaces or restricting them via firewall rules can reduce attack surface. Organizations should maintain vigilance for firmware updates from Wavlink and apply them promptly once released. Employing intrusion detection systems to detect anomalous command injection attempts and conducting regular security assessments on network devices will further reduce risk.