The scenario described involves session tokens being sent to an external URL without the users' knowledge, indicating that the web application is vulnerable to an XSS attack. An attacker has likely injected malicious JavaScript code into the web application, which is executed in the browser of any user who views the compromised page, causing their session token to be sent to the attacker's server. This scenario typically does not align with SQL injection, which involves manipulating SQL queries, or CSRF, which involves tricking a user into performing actions on a website where they are authenticated.