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Is it possible to send XSS by POST method to the victim?
One good question I was asked in Amsterdam was whether it is possible to exploit a reflected cross-site scripting bug that can only be triggered via a POST request. The answer, of course, is “yes”.
What is POST based XSS?
With a GET, you can do XSS with the URL parameters, but to exploit a POST based XSS, you need to use an HTML form(it can be disguised as link tag or whatever, but, ultimately, it is an HTML form), either on your own website, or on some other website that allows HTML forms to be created, then, inside of the HTML form …
Which of the following is the most effective defense against reflected stored XSS?
In general, effectively preventing XSS vulnerabilities is likely to involve a combination of the following measures: Filter input on arrival. At the point where user input is received, filter as strictly as possible based on what is expected or valid input. Encode data on output.
How is XSS reflected through the post method?
A large portion of sites (smaller) don’t implement CSRF tokens, so code (site functions) can be executed from anywhere on behalf of the authenticated user as you stated above. The XSS via Post is different in that it happens when the response comes back and executes the additional code (malicious payload) as a result.
Is it possible to avoid a reflected XSS attack?
Reflected attacks do not have the same reach as stored XSS attacks. Reflected attacks can be avoided by vigilant users. With a reflected XSS, the perpetrator plays a “numbers game” by sending the malicious link to as many users as possible, thereby improving his odds of successfully executing the attack.
How does sqreen work to detect reflected XSS?
To detect such non-escaped data you need to place hooks inside the templating engine. If you combine this with the parameters coming from the client in the URL, the HTTP headers or in the request’s body, you can accurately detect reflected XSS without triggering false positives. This is how Sqreen works.
How is an XSS post vulnerability different from a GET request?
The XSS via Post is different in that it happens when the response comes back and executes the additional code (malicious payload) as a result. Either way – the attacker would have to do this using those methods as it’s not possible to send someone a link for an XSS POST vulnerability like you can with a GET request.