Typically, this comments field should have configurations to validate the data before it’s sent to the database. Escape attribute if you need to insert parameters/user input data into your HTML common attributes. Don’t use event handles or attributes like href, style, or src. Contributor(s): Jim Manico, Jeff Williams, Dave Wichers, Adar Weidman, Roman, Alan Jex, Andrew Smith, Jeff Knutson, Imifos, Erez Yalon, kingthorin, Vikas Khanna. Grant Ongers har1sec, Yann C., gadhiyasavan, p4fg, diofeher, Sergey Bobrov, PwnFunction, Guilherme Keerok, Alex Brasetvik, s1r1us, ngyikp, the-xentropy, Rando111111, Fzs, Sivakumar, Dwi Siswanto, bxmbn, Tarunkant Gupta, Rando111111, laytonctf, Begeek, Hannes Leopold, yawnmoth, yawnmoth, Yair Amit, Franz Sedlmaier, Łukasz Pilorz, Steven Christey, Dan Crowley, Rene Ledosquet, Kurt Huwig, Moritz Naumann, Jonathan Vanasco, nEUrOO, Sec Consult, Timo, Ozh, David Ross, Lukasz Plonka (sp3x), xhzeem

In addition, don’t try to encode the output manually. Use element.textContent to display user-provided content, like in the following example provided by OWASP: return (typeof _ !== 'undefined'&& typeof _.template !== 'undefined'&& typeof _.VERSION !== 'undefined')This response header can be used to configure a user-agent's built in reflective XSS protection. Currently, only Microsoft's Internet Explorer, Google Chrome and Safari (WebKit) support this header. So I've been toying around with HTTP for fun in telnet now (i.e. just typing in telnet google.com 80 and putting in random GETs and POSTs with different headers and the like) but I've come across something that google.com transmits in it's headers that I don't know.

Currently this feature is enabled by default in MSIE, Safari and Google Chrome. This used to be enabled in Edge but Microsoft already removed this mis-feature from Edge. Mozilla Firefox never implemented this.Java technology is quite widely used, therefore there are many solutions to it. If you are using Spring technology and would like to escape HTML for the whole application, then you have to write the appropriate code in the project’s web.xml file. defaultHtmlEscapetrue

The closest we've got to solving this is when you have multiple injection points. The first within a script based context and the second in HTML.

Meanwhile, good testing should not be forgotten as well. It should be invested in good software testers’ knowledge and reliable software testing tools. This way good software quality will be better assured. Prevention According to Technologies