In this episode of the Nexus podcast, Bishop Fox researchers Dan Petro and David Vargas explain their research into the Open Supervised Device Protocol (OSDP), meant to bring encryption to badge readers and controllers providing physical access controls at secure facilities.
Petro and Vargas explain a number of protocol weaknesses and vulnerabilities that defeat OSDP's promise of encryption and security. Through the attacks they describe, they're able carry out—among others—replay or downgrade attacks, which are enabled by severe key exchange vulnerabilities or weakened crypto keys as described in the protocol.
Petro and Vargas unveiled this research during a presentation at Black Hat USA in Las Vegas.