CVE-2024-39227 is a critical security vulnerability identified in multiple GL-iNet router models, including AR750, AR750S, AR300M series, MT300N-V2, B1300, MT1300, SFT1200, X750, MT3000, MT2500, AXT1800, AX1800, A1300, X300B, XE300, E750, AP1300, S1300, XE3000, and X3000 across various firmware versions (notably v4.3.x to v4.5.x). The root cause is insecure permissions set on the /cgi-bin/glc endpoint, which processes JSON data. This misconfiguration allows unauthenticated attackers to send specially crafted JSON payloads that can trigger arbitrary code execution or directory traversal attacks. The vulnerability is classified under CWE-75 (Improper Neutralization of Special Elements used in a Pathname), indicating that input validation and access control are insufficient. The CVSS v3.1 base score is 9.8, reflecting network attack vector, no required privileges or user interaction, and full impact on confidentiality, integrity, and availability. Although no public exploits have been reported yet, the vulnerability's characteristics make it highly exploitable and dangerous. Attackers exploiting this flaw could gain full control over affected devices, manipulate network traffic, intercept sensitive data, or use compromised routers as pivot points for further attacks within organizational networks.

The impact of CVE-2024-39227 is severe for organizations relying on affected GL-iNet devices. Successful exploitation results in complete compromise of the router, undermining network security by allowing attackers to intercept, modify, or redirect traffic. Confidential information passing through the device can be exposed or altered, leading to data breaches and loss of integrity. The availability of network services may be disrupted if attackers deploy denial-of-service conditions or manipulate routing. Given these routers often serve as gateways or VPN endpoints, attackers could establish persistent footholds, facilitating lateral movement and further intrusions. The vulnerability's ease of exploitation without authentication increases the risk of widespread attacks, especially in environments where these devices are exposed to untrusted networks or the internet. Organizations may face operational disruptions, reputational damage, and regulatory consequences if sensitive data is compromised.

To mitigate CVE-2024-39227, organizations should immediately restrict access to the /cgi-bin/glc endpoint by implementing network segmentation and firewall rules that limit inbound traffic to trusted sources only. Disable remote management interfaces on affected devices unless absolutely necessary, and if enabled, restrict access via VPN or secure channels. Monitor network traffic for unusual JSON payloads or unexpected requests targeting the vulnerable endpoint. GL-iNet users should closely follow vendor communications for firmware updates addressing this issue and apply patches promptly once released. In the absence of patches, consider replacing affected devices with alternatives that do not exhibit this vulnerability. Additionally, conduct regular security audits of router configurations to ensure permissions and access controls adhere to the principle of least privilege. Employ intrusion detection systems capable of identifying exploitation attempts targeting this vulnerability.