The problem with universal garage door remotes is that they’re universal. If you and your neighbor ended up buying the same remote and using the same access code, you could get into each other’s garages. Still, it isn’t blatantly unsafe to have a universal remote—as long as you change the access code upon purchase and have a newer model. A potential burglar can more easily hack an old opener. Newer devices have more protections in place to prevent unauthorized access.