Trying to insert and execute a standard payload: <script>alert("XSS")</script> I can't write all text for shorter input lenght, in addition i receive this error only writing <script> tag:
Then, capturing the request using Burp Suite we can prepare a payload to give to xsser
The type of command that we need is this: xsser --url "<http://website.com" -p "payload (request that we want to test, changing the target_host value with XSS instead of example)"
Active GUI mode
There's a XSSer GUI mode that facilitate the utilize, activable with flag --gtk