What is the connection between "replay attack" to CCA security? Often in analyzing systems, the emulation of Replay Attack becomes important. Are systems that protected against CCA attacks also immune against replay attack, or it is a different criterion?
Thanks
These are different - protection against a replay attack could for example be done by recording that a message was already handled or by including a timestamp in the message and not processing the message if it is too old. 

Note that for a replay attack the attacker doesn't get the plaintext, but does get access to at least 1 previously sent message. In CCA the attacker doesn't not have access to previously sent messages, and can request back the plaintext for chosen ciphertexts.