An issue was discovered in amqp_handle_input in amqp_connection.c in rabbitmq-c 0.9.0. There is an integer overflow that leads to heap memory corruption in the handling of CONNECTION_STATE_HEADER. A rogue server could return a malicious frame header that leads to a smaller target_size value than needed. This condition is then carried on to a memcpy function that copies too much data into a heap buffer.