CVE-2025-15389 identifies a critical OS Command Injection vulnerability in the VPN Firewall product developed by QNO Technology. This vulnerability stems from improper neutralization of special elements used in OS commands (CWE-78), allowing authenticated remote attackers to inject arbitrary operating system commands that the server executes with the privileges of the VPN firewall process. The vulnerability requires the attacker to have some level of authentication (PR:L - privileges required are low), but does not require user interaction (UI:N), making it easier to exploit remotely. The CVSS 4.0 base score of 8.7 reflects the high impact on confidentiality, integrity, and availability, with network attack vector (AV:N) and low attack complexity (AC:L). The vulnerability affects all versions indicated as '0' (likely meaning all current versions or an unspecified version range). No patches are currently available, and no known exploits have been reported in the wild, but the potential for exploitation is significant given the nature of VPN firewalls as critical network security devices. Attackers exploiting this vulnerability could gain control over the firewall, manipulate traffic, exfiltrate data, or disrupt network connectivity. The vulnerability was published on December 31, 2025, and assigned by TW-CERT. The lack of segmentation or sandboxing in the vulnerable component likely contributes to the high impact. The vulnerability is categorized under CWE-78, emphasizing the importance of proper input validation and command sanitization in security-critical software.

For European organizations, the impact of this vulnerability is substantial due to the critical role VPN firewalls play in securing remote access and internal network segmentation. Exploitation could lead to unauthorized command execution, resulting in data breaches, network disruption, or complete takeover of the VPN firewall device. This could compromise sensitive corporate or governmental communications, disrupt business operations, and potentially serve as a foothold for further lateral movement within networks. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk. The high CVSS score indicates a severe threat to confidentiality, integrity, and availability. Since the vulnerability requires authentication but no user interaction, insider threats or compromised credentials could facilitate exploitation. The absence of known exploits currently provides a window for proactive mitigation, but the risk of future exploitation remains high. The impact is magnified in environments where QNO VPN Firewalls are widely deployed or where alternative security controls are limited.

1. Immediate action should focus on monitoring and restricting access to the VPN firewall management interfaces to trusted personnel only, enforcing strong authentication mechanisms such as multi-factor authentication (MFA). 2. Network segmentation should be implemented to isolate the VPN firewall management network from general user networks to reduce exposure. 3. Deploy strict input validation and command sanitization controls if custom scripts or configurations are used in conjunction with the VPN firewall. 4. Monitor logs and network traffic for unusual command execution patterns or anomalous behavior indicative of exploitation attempts. 5. Engage with QNO Technology for updates and patches; apply security patches promptly once available. 6. Conduct regular vulnerability assessments and penetration testing focused on VPN infrastructure to detect similar issues. 7. Implement an incident response plan specific to VPN firewall compromise scenarios. 8. Restrict VPN firewall administrative access to dedicated, secure management workstations with hardened configurations. 9. Consider deploying additional endpoint detection and response (EDR) tools on VPN firewall hosts if supported. 10. Educate administrators on the risks of credential compromise and enforce strict password policies.