CVE-2024-39226 is a command injection vulnerability identified in various 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 firmware versions 4.3.11 through 4.5.16 and others as specified. The vulnerability arises from insufficient input sanitization in the s2s API, which handles server-to-server communication. Attackers can exploit this flaw by sending crafted requests containing malicious shell commands, leading to command injection (CWE-77). This allows execution of arbitrary commands on the router without requiring authentication or user interaction. The CVSS v3.1 base score is 4.3, reflecting a medium severity primarily due to the attack vector being adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The impact is limited to availability (A:L), with no direct confidentiality or integrity compromise. No patches or known exploits are currently reported, but the vulnerability poses a risk of denial of service or disruption of network operations if exploited.

The primary impact of CVE-2024-39226 is on the availability of affected GL-iNet routers. Successful exploitation can lead to denial of service conditions, potentially causing network outages or degraded performance. While confidentiality and integrity are not directly compromised, disruption of router functionality can affect business continuity, especially in environments relying on these devices for critical connectivity. Organizations using these routers in enterprise, industrial, or remote access scenarios may face operational interruptions. The lack of authentication requirement and low attack complexity increase the risk of exploitation from adjacent networks, such as local LANs or VPNs. Although no known exploits exist yet, the vulnerability could be leveraged by attackers to disrupt services or as a stepping stone for further attacks if combined with other vulnerabilities.

1. Restrict access to the s2s API by implementing network segmentation and firewall rules to limit exposure to trusted hosts only. 2. Monitor network traffic for unusual or malformed requests targeting the s2s API endpoints. 3. Disable the s2s API if it is not required for your deployment to reduce the attack surface. 4. Apply firmware updates from GL-iNet promptly once patches addressing this vulnerability are released. 5. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to detect command injection attempts. 6. Conduct regular security assessments and penetration testing focusing on router management interfaces. 7. Maintain an inventory of affected devices and track their firmware versions to prioritize remediation. 8. Educate network administrators about this vulnerability and the importance of securing router management interfaces.