The vulnerability stems from two key factors:

1. Improper file permissions: The restapi.service file is writable by www-data, allowing modification of systemd service commands.
2. Excessive sudo privileges: www-data can execute systemctl and reboot commands without authentication.

While specific function names aren't provided in the advisory, the attack flow demonstrates that:

• The ability to modify restapi.service (CWE-269) enables command injection via service configuration (CWE-77)
• Sudo privileges allow these modified commands to execute as root These manifest in the systemd service definition and sudoers configuration files rather than discrete application functions, as the vulnerability is primarily a misconfiguration issue.