PHP PHPSESSID exploit confusion
<p>I am confused about the PHPSESSID exploit. If I change <code>document.cookie</code> to another active user's (on a simple social media site like youtube or instagram [just an example]) <code>PHPSESSID</code>, will the page reload with me being logged into that user's account? Will I also need to know that user's password? Note: I will not actually do that but I want to learn what would happen. Thank you!</p>

<p>P.S I am not familiar with this so please excuse my lack of knowledge:)</p>