A penetration tester evaluates a company's secure web application, which uses HTTPS, secure cookie flags,...

CEH materials explain that modern web applications deploy multiple layers of security—HTTPS, secure cookies, HttpOnly flags, and strict session regeneration—to defend against standard hijacking methods such as token theft through XSS or fixation. When these protections are properly implemented, attackers must compromise the underlying trust relationship between the client and server to successfully intercept or manipulate session tokens. One of the most advanced techniques described in CEH is compromising a trusted certificate authority or injecting a forged certificate into the victim’s trust store. This enables the attacker to perform a transparent MITM attack despite HTTPS protections. Because the victim’s browser trusts the forged certificate, encrypted traffic—including session tokens—is exposed to the attacker without generating browser warnings or IDS alerts. Timing side-channel attacks are not considered session hijacking methods; XSS is mitigated by secure flags; and session fixation is ineffective when session regeneration occurs. Therefore, compromising a trusted certificate authority to enable an undetectable MITM attack is the most viable method.