What is cross-site scripting (XXS)?

Cross-site scripting (XSS) is a type of security vulnerability that can occur in Web applications and Web sites. XSS attacks involve injecting malicious JavaScript code into a Web application, which can then be executed by other users when they visit the site. This allows attackers to steal sensitive information, such as passwords or financial data, or manipulate the appearance or behavior of the application.

XSS vulnerabilities can occur when a Web application or Web site adopts user-supplied input into the page without properly validating or encoding the input. This allows attackers to inject their own code into the site, which can then be executed by other users when they visit the site. For example, if a Web site allows users to post comments, an attacker could insert malicious JavaScript code into their comment, which could then be executed by other users when they view the comment on the site.

What is the difference between reflective or persistent XSS?

The main difference between reflective and persistent XSS is how the malicious code, or XSS payload, is stored and executed. In reflective XSS, the payload is injected into a website, which is then returned to the user. This type of attack is usually carried out through a URL that contains the injected code and the code is executed when the user clicks on the link. Persistent XSS, on the other hand, injects the malicious code directly into the website, where it is stored in the database. This type of attack is more dangerous because it only needs to be injected once and can then come back to other users.

How can cross-site scripting be prevented?

To protect against XSS attacks, it is important that programmers correctly validate and clean up user-supplied input. This may involve the use of techniques such as input filtering and output coding to ensure that only permitted characters and data are included in the output of the Web site or Web application. It is also important to keep the Web application or Web site up-to-date with the latest security patches to use to minimize the risk of XSS vulnerabilities. In fact, plug-ins can also contain vulnerabilities, such as XSS.

XSS is a serious vulnerability that can affect Web applications and Web sites. By correctly validating and cleaning user-supplied input and following secure programming standards such as the OWASP secure coding practices, Web developers can protect themselves from XSS attacks and protect their users from these types of vulnerabilities. Want to know if your application is safe from XSS? In a pen test and Website Security Check, CyberAnt checks your application for XSS.