CVE-2025-66575 identifies a critical security vulnerability in VeePN's VeeVPN software version 1.6.1, specifically an unquoted search path or element vulnerability classified under CWE-428. The flaw exists in the VeePNService, a Windows service component, where the service executable path is not properly quoted. This misconfiguration allows attackers to insert malicious executables or commands into the service path. During system startup or reboot, Windows attempts to execute the service using the unquoted path, which can be hijacked if an attacker places a malicious binary or script in a directory that is parsed earlier in the search path. Exploiting this vulnerability enables remote attackers to execute arbitrary code with LocalSystem privileges, the highest level of access on a Windows system. The attack vector requires user interaction, such as triggering a reboot or startup sequence, but does not require prior authentication, increasing the risk profile. The CVSS 4.0 score of 8.5 reflects the high impact on confidentiality, integrity, and availability, combined with relatively low attack complexity. No patches are currently listed, and no known exploits have been observed in the wild, but the vulnerability presents a significant risk if weaponized. This vulnerability is particularly dangerous because it allows privilege escalation from a potentially low-privileged context to full system control, which can lead to persistent backdoors, data theft, or system sabotage.

For European organizations, the impact of CVE-2025-66575 is substantial. Successful exploitation results in full system compromise with LocalSystem privileges, enabling attackers to bypass security controls, access sensitive data, and disrupt operations. Organizations relying on VeeVPN 1.6.1 for secure communications or remote access could see confidentiality breaches, integrity violations, and availability disruptions. Critical infrastructure, government agencies, and enterprises in sectors such as finance, healthcare, and energy are particularly vulnerable due to the potential for espionage or sabotage. The vulnerability's ability to escalate privileges without authentication increases the risk of lateral movement within networks, potentially leading to widespread compromise. Additionally, the lack of current patches means organizations must rely on interim mitigations, increasing operational complexity and risk exposure. The threat is amplified in environments where VeeVPN is widely deployed and integrated into security architectures.

1. Immediately audit all systems running VeeVPN version 1.6.1 to identify vulnerable installations. 2. Restrict NTFS permissions on the directories containing the VeePNService executable to prevent unauthorized users from writing or placing malicious files in the service path. 3. Implement application whitelisting to block execution of unauthorized binaries in service-related directories. 4. Monitor system event logs and service configurations for unauthorized changes or suspicious activity related to VeePNService. 5. Enforce strict user privilege management to limit the ability of non-administrative users to modify service configurations or file system paths. 6. Where possible, isolate systems running VeeVPN in segmented network zones to reduce exposure. 7. Engage with VeePN vendor support to obtain patches or official guidance and apply updates promptly once available. 8. Educate users about the risks of triggering system reboots or startups without verifying system integrity. 9. Employ endpoint detection and response (EDR) tools to detect anomalous process executions and privilege escalations. 10. Consider temporary alternative VPN solutions if patching is delayed, especially in high-risk environments.