motionEye (mEye) is an online interface for a piece of software called "motion," which is a video surveillance program with motion detection. Prior to 0.44.0, motionEye accepts the client-controlled meye_username and meye_password_hash cookies as authentication material without server-side session validation. An unauthenticated attacker who knows a target username and corresponding hash can set the cookies manually or cause them to be loaded by submitting blank credentials through the switch-user authentication flow, after which the server authenticates the attacker as that user. The administrator username and password-hash value are stored in /etc/motioneye/motion.conf, which is globally readable by default, allowing a local shell user to obtain reusable administrator credential…