Cookies and Computer Security

By John King, CISSP, PMP, CISM •  Updated: 01/03/23 •  3 min read

Cookies are small text files that are stored on a user’s computer by a website. They are used to remember information about the user, such as their preferences or login status. While cookies can be useful for improving the user experience, they can also pose a security risk if not managed properly.


One potential security risk of cookies is that they can store sensitive information, such as login credentials or personal data. If this information is stored in an unencrypted cookie, it can potentially be accessed by hackers. This is why it is crucial for websites to use secure connections (https) when handling sensitive information and to set the “secure” flag on cookies that contain sensitive information.
Another potential security risk is that cookies can be used to track a user’s online activities. This is often done for advertising purposes, but it can also be used for more malicious purposes, such as creating a profile of the user’s interests or habits. This information can then be sold to third parties or used to target the user with malicious content.


To protect against these risks, users can take a few precautions. One option is to disable cookies in the web browser. This can be done in the browser settings, but it may impact the functionality of some websites. Another option is to use a private browsing mode, which prevents the browser from storing cookies or other browsing data.


Users can also use browser extensions to manage cookies. These extensions allow the user to block or delete cookies from specific websites or block all cookies except those from websites that the user trusts. Some extensions also allow the user to block tracking cookies or to block cookies from third-party websites.


Another option for protecting against the risks of cookies is to use a virtual private network (VPN). A VPN encrypts the user’s internet connection and can prevent cookies from being stored or accessed by third parties. However, it is important to note that a VPN will not protect against all security risks, and it is still important to use caution when browsing the internet.


It is also important for websites to take steps to protect against the security risks of cookies. This includes using secure connections, setting the “secure” flag on cookies with sensitive information, and implementing measures to prevent cross-site scripting (XSS) attacks, which can allow an attacker to inject malicious code into a website and access cookies.


In summary, cookies can be useful for improving the user experience, but they can also pose a security risk if not managed properly. To protect against these risks, users can disable cookies in their web browser, use a private browsing mode, use cookie management extensions, or use a VPN. Websites can also take steps to protect against the security risks of cookies by using secure connections, setting the “secure” flag on sensitive cookies, and implementing measures to prevent XSS attacks.

John King, CISSP, PMP, CISM

John King currently works in the greater Los Angeles area as a ISSO (Information Systems Security Officer). John has a passion for learning and developing his cyber security skills through education, hands on work, and studying for IT certifications.