In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, the faxsetup utility calls chown on files in user-owned directories. By winning a race, a local attacker could use this to escalate his privileges to root.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.