When a cookie is protected with the secure attribute set to true it will not be send by the browser over an unencrypted HTTP
request and thus cannot be observed by an unauthorized person during a man-in-the-middle attack.
Ask Yourself Whether
- the cookie is for instance a session-cookie not designed to be sent over non-HTTPS communication.
- it’s not sure that the website contains mixed content or not
(ie HTTPS everywhere or not)
There is a risk if you answered yes to any of those questions.
Recommended Secure Coding Practices
- It is recommended to use
HTTPs everywhere so setting the secure flag to true should be the default behaviour
when creating cookies.
- Set the
secure flag to true for session-cookies.
Sensitive Code Example
If you create a security-sensitive cookie in your JAVA code:
Cookie c = new Cookie(COOKIENAME, sensitivedata);
c.setSecure(false); // Sensitive: a security-ensitive cookie is created with the secure flag set to false
By default the secure flag is set
to false:
Cookie c = new Cookie(COOKIENAME, sensitivedata); // Sensitive: a security-sensitive cookie is created with the secure flag not defined (by default set to false)
Compliant Solution
Cookie c = new Cookie(COOKIENAME, sensitivedata);
c.setSecure(true); // Compliant: the sensitive cookie will not be send during an unencrypted HTTP request thanks to the secure flag set to true
See
