Tomcat and HttpOnly Session Cookies

Just wanted to let you know that Apache Tomcat can now be configured to use HttpOnly session cookies. I had forgotten about Jim Manico's crusadeto get HttpOnly support in Tomcat. It is a shame that it took so long to happen. Microsoft had introduced the concept of HttpOnly cookies primarily as a defense against session hijacking where a cross-site scripting attack is used to steal a session cookie. If a web application sets a cookie with the HttpOnly attribute, web browsers do not allow client-side script to access the cookie. The first browser to support HttpOnly was Internet Explorer 6 SP1 and for a long while IE was the only browser that supported it. That has changed. Firefox and Opera, for example, now support HttpOnly as well.

In Tomcat, enabling HttpOnly for the JSESSIONID is done at the context level, which means it can be controlled for each individual web application. You simply need need to add the following attribute to the <context> element:

useHttpOnly="true"

The default is "false", so you must explicitly add the line above to implement an HttpOnly session cookie. This capability first appeared in Tomcat 6.0.19 (current version = 6.0.20) as well as Tomcat 5.5.28, which is currently the latest version in the 5.5 branch.