6.2Key protocols and network applications

Many network application protocols were designed in the 1980s-90s under a "good faith" assumption, so the standard behavior of the protocol itself carries an inherent attack surface. DNS recursive queries can be fertile ground for cache poisoning, and cookie-based session management can be a target for session hijacking. This section builds the judgment to understand each protocol's mechanics and then determine where the attack surface lies and how to design to reduce the risk.

6.2.1HTTP and HTTPS

• HTTP is the Web's application-layer protocol, and being plaintext itself, it is defenseless against eavesdropping and tampering (a man-in-the-middle attack). HTTPS is HTTP encrypted with TLS, providing confidentiality (preventing eavesdropping), integrity (detecting tampering), and server authentication (confirming connection to the legitimate server).
• Even with HTTPS deployed, an implementation that skips certificate validation, or a configuration that still permits old TLS versions (SSLv3, TLS 1.0, etc.), leaves a residual man-in-the-middle risk. A design decision to permit only recommended cipher suites and protocol versions, in line with the SSL/TLS cryptographic configuration guidelines, is required.