Host code execution via crash-dump path traversal

Path traversal in Parallels Desktop before 18.1.1 allows local users with privileged guest access to write files on the macOS host. The Toolgate crash-dump handler concatenates a guest-controlled process name with the GuestDumps directory, and an embedded null truncates the suffix before QFile writes attacker-supplied data. Exploitation requires high-privileged code execution inside a guest and can overwrite host-user files, enabling code execution as that host user.