A lot of articles underline that XSS vulnerabilities can be very dangerous for the website on which they exist. I wonder how much is this true when we find these XSS vulnerabilities on the frontend of a website, in fields such as the search forms?
Cross-site scripting vulnerabilities are extremely dangerous, because they allow the attacker to control the victim's browser to some extend.
This can be used for all kinds of malicious actions:
- stealing sensitive cookies or reading personal pages (the user account, private messages etc.)
- making requests on the victim's behalf (e. g., ordering products via the victim's account and sending them to an arbitrary address)
- exploting the trust of the victim in the site; for example, an attacker might render a fake login form and prompt the user to enter the password. Or they might trick the user into downloading a malicious file which looks like it's served by the site.
- attacking the server through a privileged account
So while XSS may look less dangerous than, say, SQL injections at first site, it's actually a major threat for both your users and your server.