Hundreds of garage doors could be vulnerable to a recent hack that uses a modified children's toy to test thousands of lock combinations in seconds.

Samy Kamkar, a security researcher, wrote on his website that his tool, “OpenSesame,” allows him to open any garage door that uses a fixed code system to communicate with its wireless remote. His makeshift device, designed from a Mattel toy called the IM-ME, can test every garage combination and open it in seconds. The IM-ME, which is now discontinued, can receive and transmit on frequencies under one Gigahertz.

Garage doors that have “rolling code,” “hopping codes,” “Security+,” or “Intellicode” are not vulnerable to OpenSesame or more traditional brute force attacks, Kamkar noted.  These codes change with each button press.

Kamkar posted his source code online but altered it to prevent criminal use.