What is cross-site scripting (XXS)?

Cross-site scripting (XSS) is a type of security vulnerability that can affect web applications and websites. XSS attacks involve injecting malicious code into a website or web application, which can then be executed by other users when they access the affected site. This can allow attackers to steal sensitive information, such as user credentials or financial data, or to manipulate the appearance or behavior of the site for their own purposes.

XSS vulnerabilities can arise when a web application or website includes user-supplied input in its output without properly validating or sanitizing the input. This can allow attackers to inject their own code into the site, which can then be executed by other users when they access the site. For example, if a website allows users to post comments, an attacker could include malicious JavaScript code in their comment, which could then be executed by other users when they view the comment on the site.

What is the difference between reflective XSS and persistent XSS?

The main difference between reflective and persistent XSS is the way in which the malicious code is stored and executed. Reflective XSS involves injecting the payload into a website, which is then reflected back to the user. This type of attack is typically 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, involves injecting the malicious code directly into the website, where it is permanently stored. This type of attack is more difficult to detect and prevent, because the code is executed every time the page is loaded.

How to prevent cross-site scripting

To protect against XSS attacks, it is important for web developers to properly validate and sanitize user-supplied input. This can involve using techniques such as input filtering and output encoding to ensure that only allowed characters and data are included in the website or web application’s output. It is also important to keep the web application or website up to date with the latest security patches and to use secure coding practices to minimize the risk of XSS vulnerabilities.

In conclusion, XSS is a serious security threat that can affect web applications and websites. By properly validating and sanitizing user-supplied input and following secure coding practices, like the OWASP Secure Coding Practices, web developers can protect against XSS attacks and keep their users safe from this type of security threat.


More information about our solutions

Do you want to make sure that your websites, apps or systems are free from vulnerabilities? Our experts are happy to work for you. For more information about our pentests or other services, please feel free to contact us via the contact form below. We are happy to tell you what we can do for you.


    Randstad 22 147
    1316BM Almere

    +31 (0)85 047 1590