Weak Session IDs

Objective

This module uses four different ways to set the dvwaSession cookie value, the objective of each level is to work out how the ID is generated and then infer the IDs of other system users.

Security Level: Low

The cookie value should be very obviously predictable.

• Let's inspect the page and check for the cookies.

• As we can see, the dvwaSession cookie is set to 1. Let's click on the Generate button and check what happens.

• The dvwaSession cookie is now set to 1. Now we know that the application increments the cookie every time the user clicks on the Generate button.

• We could also check the provided source code to be sure.

Security Level: Medium

The value looks a little more random than on low but if you collect a few you should start to see a pattern.

• In this level the value of the dvwaSession cookie increments by 1 the first we click the button and then by 2.

• This process is repeated as many times as the user clicks the button.