CVE-2024-39798 is a critical security vulnerability classified under CWE-15 (External Control of System or Configuration Setting) affecting the Wavlink AC3000 router firmware version M33A8.V5030.210505. The flaw resides in the openvpn.cgi script, specifically within the openvpn_server_setup() function, which processes configuration parameters for the OpenVPN server setup. The vulnerability allows an authenticated attacker to send specially crafted HTTP POST requests, manipulating the 'sel_open_protocol' parameter to inject arbitrary configuration commands. This injection leads to arbitrary command execution on the device, effectively granting the attacker full control over the router’s operating system. The vulnerability requires the attacker to have valid authentication credentials to the device’s management interface but does not require user interaction beyond that. The CVSS v3.1 base score is 9.1, reflecting the high impact on confidentiality, integrity, and availability, as well as the network attack vector and low attack complexity. Although no known exploits are currently reported in the wild, the critical nature of this vulnerability means it could be leveraged for persistent network compromise, interception of traffic, or pivoting to internal networks. The vulnerability affects a specific firmware version, indicating that other versions may not be vulnerable, but organizations using this firmware should consider immediate remediation. The lack of available patches at the time of reporting necessitates interim mitigations such as restricting access to the management interface and disabling OpenVPN server functionality if not required.

For European organizations, the impact of CVE-2024-39798 is significant due to the potential for complete compromise of affected Wavlink AC3000 routers. Successful exploitation can lead to unauthorized access to internal networks, interception and manipulation of sensitive data, disruption of network services, and use of the compromised device as a foothold for further attacks. This is particularly critical for enterprises, government agencies, and critical infrastructure operators relying on these routers for secure VPN connectivity. The breach of confidentiality could expose sensitive communications, while integrity and availability impacts could disrupt business operations and critical services. Given the router’s role in network perimeter defense and VPN termination, exploitation could undermine trust in network security and compliance with data protection regulations such as GDPR. The requirement for authentication reduces the risk from external attackers without credentials but insider threats or credential compromise scenarios remain high risk. The absence of public exploits currently provides a limited window for mitigation before potential weaponization.

1. Immediately verify if your Wavlink AC3000 devices are running the vulnerable firmware version M33A8.V5030.210505. 2. Monitor Wavlink’s official channels for firmware updates or patches addressing CVE-2024-39798 and apply them promptly once available. 3. Restrict access to the router’s management interface to trusted IP addresses and networks only, ideally via VPN or secure management VLANs. 4. Enforce strong authentication mechanisms and rotate credentials regularly to reduce the risk of credential compromise. 5. Disable the OpenVPN server functionality on the device if it is not required, to eliminate the attack surface. 6. Implement network segmentation to limit the impact of a compromised router on the broader network. 7. Employ network monitoring and intrusion detection systems to detect anomalous configuration changes or command execution attempts on the router. 8. Conduct regular security audits and penetration tests focusing on network infrastructure devices. 9. Educate network administrators on the risks of configuration injection vulnerabilities and the importance of secure device management practices.