Threat actors can record and replay TC/TM packets to deceive the spacecraft or the ground station, causing an unexpected behavior or an erroneous evaluation of the spacecraft status. Threat actors can gain access to the data exchanged in a payload channel or even spoof TC. Usually the TM replay doesn't cause an impact, unless timing information are transmitted.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.