Use of Insufficiently Random Values

Summary

An issue was discovered in Neato Botvac Connected 2.2.0. The GenerateRobotPassword function of the NeatoCrypto library generates insufficiently random numbers for robot secret_key values used for local and cloud authentication/authorization. If an attacker knows the serial number and is able to estimate the time of first provisioning of a robot, he is able to brute force the generated secret_key of the robot. This is because the entropy of the secret_key exclusively relies on these two values, due to not seeding the random generator and using several constant inputs for secret_key computation. Serial numbers are printed on the packaging and equal the MAC address of the robot.