Tigo Energys CCA device is vulnerable to insecure session ID generation in their remote API. The session IDs are generated using a predictable method based on the current timestamp, allowing attackers to recreate valid session IDs. When combined with the ability to circumvent session ID requirements for certain commands, this enables unauthorized access to sensitive device functions on connected solar optimization systems.
A Pseudo-Random Number Generator (PRNG) is initialized from a predictable seed, such as the process ID or system time.