Cross-site-scripting

Cross-site scripting (XSS) is a type ofcomputer security vulnerability typically found in web applications. XSS enables attackers toinject client-side scripts into web pagesviewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass access controls such as the same-origin policy. Cross-site scripting carried out on websites accounted for roughly 84% of all security vulnerabilities documented bySymantec as of 2007.^[1] Bug bounty companyHackerOne in 2017 reported that XSS is still a major threat vector.^[2] XSS effects vary in range from petty nuisance to significant security risk, depending on the sensitivity of the data handled by the vulnerable site and the nature of any security mitigation implemented by the site's owner.