What are the consequences of not deleting HTTP cookies?

• A. They never expire
• B. They accelerate login
• C. Attackers may steal user authentication credentials.
• D. They prevent cookies from being saved locally.

Answer: (C)

Not deleting HTTP cookies leaves session data on your device. When you log in, the site often stores a session cookie that proves you’re authenticated on subsequent requests. If that cookie persists, someone who gains access to your computer or browser—through malware, a stolen device, or a shared machine—can reuse that token to access your account without needing your password. This is a form of session hijacking and is the main security risk of leaving cookies around. Cookies do have expiration settings, so they don’t necessarily last forever; many cookies expire or are cleared when you close the browser, but others persist much longer. Since cookies are saved locally, deleting them removes those authentication tokens from your device. So the key consequence is the increased chance that attackers can steal your authentication state and take over accounts if they can access your browser. To mitigate, regularly log out, clear cookies when on shared devices, and prefer security flags like HttpOnly and Secure where available.