CVE-2019-25343 in NextVPN
Summary
by MITRE • 02/12/2026
NextVPN 4.10 contains an insecure file permissions vulnerability that allows local users to modify executable files with full access rights. Attackers can replace system executables with malicious files to gain SYSTEM or Administrator privileges through unauthorized file modification.
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Analysis
by VulDB Data Team • 02/12/2026
The vulnerability identified as CVE-2019-25343 resides within NextVPN version 4.10 and represents a critical insecure file permissions flaw that fundamentally compromises system integrity. This vulnerability specifically targets the application's handling of file permissions during installation and operation, creating a persistent security weakness that can be exploited by local attackers. The flaw allows unauthorized modification of executable files due to overly permissive access controls that grant excessive privileges to local users who should not possess such elevated rights. The vulnerability's severity is amplified by its local nature, as it does not require network connectivity or remote exploitation, making it particularly dangerous in environments where physical access is possible.
The technical implementation of this vulnerability stems from NextVPN 4.10's failure to properly enforce access controls on critical system files and directories. When the application installs or operates, it creates executable files and system components with world-writable permissions or permissions that allow local users to modify critical system binaries. This misconfiguration directly violates security best practices and creates a privilege escalation vector that can be leveraged to gain SYSTEM or Administrator privileges. The vulnerability aligns with CWE-732: Incorrect Permission Assignment for Critical Resources, which specifically addresses the assignment of insufficient permissions to security-critical resources. Attackers can exploit this by replacing legitimate system executables with malicious counterparts, effectively creating a backdoor or persistence mechanism within the target system.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise and potential data exfiltration. Local attackers who exploit this vulnerability can execute arbitrary code with the highest available privileges, enabling them to install rootkits, modify system configurations, establish persistent access, and potentially move laterally within network environments. The vulnerability creates a persistent threat that can survive system reboots and remains undetected by standard security monitoring tools. From an adversarial perspective, this vulnerability maps to multiple ATT&CK techniques including privilege escalation through file permission modification, persistence via legitimate system binaries, and defense evasion by maintaining access through legitimate system components.
Mitigation strategies for CVE-2019-25343 should focus on immediate remediation through proper permission enforcement and system hardening. Organizations must ensure that all executable files and system components are protected with appropriate access controls, typically requiring read-only permissions for non-privileged users and restricted write access for administrators only. The recommended approach involves updating NextVPN to a patched version that properly implements secure file permissions, or implementing temporary workarounds such as restricting local user access to critical system directories. Security administrators should conduct thorough permission audits of all system files and directories to identify and correct similar vulnerabilities. Additionally, implementing application whitelisting policies and monitoring for unauthorized file modifications can provide additional layers of protection against exploitation attempts. The vulnerability highlights the critical importance of proper access control implementation and demonstrates how seemingly minor permission misconfigurations can lead to complete system compromise.