CVE-2024-38896 identifies a command injection vulnerability in the WAVLINK WN551K1 router model. The flaw exists in the handling of the start_hour parameter within the /cgi-bin/nightled.cgi CGI script. Due to insufficient input validation and sanitization, an attacker can inject arbitrary OS commands remotely without authentication or user interaction. This vulnerability falls under CWE-77, which involves improper neutralization of special elements in commands, allowing attackers to manipulate system commands executed by the device. The vulnerability has a CVSS 3.1 score of 5.3, indicating medium severity, with an attack vector over the network, low complexity, no privileges required, and no user interaction needed. The impact is limited to confidentiality loss, with no direct integrity or availability effects reported. No patches or official fixes have been released at the time of publication, and no known exploits have been observed in the wild. The vulnerability could be leveraged by attackers to gain unauthorized access to the device, potentially enabling further network reconnaissance or pivoting attacks within affected environments. Given the nature of the device as a network router, successful exploitation could compromise network traffic or enable persistent footholds in organizational networks.

The primary impact of CVE-2024-38896 is unauthorized remote command execution on the WAVLINK WN551K1 router, which can lead to partial confidentiality breaches such as exposure of sensitive configuration or network information. Although the vulnerability does not directly affect integrity or availability, attackers could use the foothold to conduct further attacks, including network reconnaissance, lateral movement, or deployment of malware. Organizations relying on these routers for network connectivity or security may face increased risk of internal network compromise. The vulnerability’s ease of exploitation (no authentication or user interaction required) increases its threat potential. However, the absence of known exploits and the medium CVSS score suggest the immediate risk is moderate. Still, unpatched devices in critical infrastructure or enterprise environments could be targeted by advanced threat actors. The impact is more significant in environments where these routers are exposed to untrusted networks or the internet, increasing the attack surface.

1. Immediate mitigation includes isolating affected WAVLINK WN551K1 devices from untrusted networks or the internet to reduce exposure. 2. Monitor network traffic for unusual activity or command injection attempts targeting the /cgi-bin/nightled.cgi endpoint. 3. Implement network segmentation to limit the impact of a compromised router on internal systems. 4. Regularly audit and update router firmware; although no patch is currently available, stay informed on vendor advisories for official fixes. 5. Employ web application firewalls (WAF) or intrusion detection/prevention systems (IDS/IPS) with signatures or rules to detect and block command injection patterns targeting this vulnerability. 6. Restrict access to router management interfaces to trusted IP addresses only and disable remote management if not required. 7. Conduct penetration testing or vulnerability scanning focused on command injection vectors on network devices. 8. Prepare incident response plans to quickly isolate and remediate affected devices if exploitation is detected.