There's a bug in aws_mqtt.c (WICED 6.4) when receiving a long messages on a subscribed topic (e.g. AWS CreateKeysAndCertificate provisioning message response)
In such case the message is broken into chunks that are being transferred on several calls to mqtt_connection_event_cb(...).
The topic is carried in the first chunk and need to be stored in an allocated memory, not just being pointed at (as its pointing to temporary object).
Attached is a screen cap of the change required (on the right pane)
NOTE - There is still unhandled vulnerability if the topic name itself is very long and crosses a chunk boundary !
Cypress/Infineon - please handle this vulnerability !!!
Thanks for bringing this to our notice. We will review this bug and get back to you if we have any further feasibility query.