The CEH v13 courseware states that insecure communication occurs when mobile applications transmit sensitive data over unencrypted or weakly encrypted channels, exposing information to interception. When an application uses plain HTTP or does not properly validate certificates, attackers can place themselves between the client and server using a man-in-the-middle (MitM) attack. This allows them to read session tokens, credentials, API keys, or personal user data as it travels across the network. CEH materials emphasize that MitM attacks are the primary exploitation technique for insecure data transmission because they exploit weaknesses in transport-layer security rather than weaknesses in backend code or authentication mechanisms. SQL injection and CSRF attacks target web application logic, not transport encryption. Brute-force attacks target authentication mechanisms and are unrelated to how data is transmitted. Therefore, the most effective exploitation method is intercepting traffic via MitM to capture or manipulate unencrypted communications.