Some protocols transmit access credentials in the clear (Telnet, HTTP, and FTP). Using a packet sniffer such as Wireshark will allow an attacker to intercept and reuse the credentials.
However, most remote access protocols, especially those embedded in the operating system, are now protected with access controls and encryption. Although this adds a degree of security, they are still subject to attacks that may occur due to misconfigurations or the use of poor encryption keys. In this section, we will examine other risks that can be exploited to compromise supposedly secure communication channels.