What is XSS (Cross-Site Scripting) Attack?

what is xss cross site scripting attack.

What is XSS (Cross-Site Scripting) Attack?

What is XSS Attack

Protection against top vulnerabilities such as Cross-Site Scripting (XSS) is critical because sites store critical information. XSS attacks can have a wide range of damage from hackers spreading worms on websites to hackers stealing sensitive data such as identity theft or even committing financial crimes. So what is an XSS attack?

Also read: 10 Commonly Used Cyber ​​Attacks


1. What is an XSS Attack?

2. XSS Attack Type

3. 1. Reflected XSS

4. 2. Stored XSS

5. 3. DOM XSS

6. How XSS Attacks Work

7. Impact of XSS Attack

8. Prevent XSS Attacks

9. 1. Site Security Analysis

10. 2. Added SDL

11. 3. Adopt a Crossing Boundaries Policy

12. 4. Using Correct Meta Tags

13. Conclusion

What is an XSS Attack?

Cross-Site Scripting or XSS attack is a security exploit in which an attacker places malicious client-end code into a web page.

This has been the most prevalent attack that has been around for more than three decades now. All major websites have been affected by the exploitation of this vulnerability.

Attackers using XSS vulnerabilities steal user data, or control user sessions, run malicious code or even use it as a major component of phishing scams.

XSS Attack Type

XSS attacks can be broadly classified into the following 3 categories:

1. Reflected XSS

Reflected XSS is also known as a persistent or persistent XSS attack. In the case of a reflected XSS attack, the malicious script is reflected to another website in the user's browser. This occurs when user input from a URL or POST data is reflected on the page without being saved, thus allowing attackers to inject malicious content.

This means that an attacker must send a malicious URL or post form to the victim to enter the payload, and the victim must click on the link. This kind of payload is also generally captured by the built-in XSS filter in the user's browser, such as Chrome, Internet Explorer or Edge.

2. Stored XSS

Stored XSS, also known as persistent XSS, includes inserting malicious code directly into web applications. This occurs when the payload is stored, for example in a database and then executed when the user opens a page in a web application.


DOM XSS is a form of XSS attack in which malicious scripts are present in the Document Object Model instead of HTML. In a reflected and stored Cross-Site Scripting attack, you can see the vulnerability payload in the response page but in DOM based XSS, the HTML source code and the attack response will be exactly the same, i.e. the payload cannot be found in the response. It can only be observed at runtime or by investigating the page's DOM.

How XSS Attacks Work

XSS attacks are different from most application layer attacks. Here, the attacker attacks the user's application and not the application or its servers. XSS attacks work by placing malicious code, usually using a client-side script, into the output of a web application.

Traditionally, most websites have had some point of injection such as search fields, online feedback forms, cookies that appear as soft targets for any cross-site scripting.

One of the most common motives behind XSS attacks is to gain insights from cookie data. Because cookies are usually used in the wrong method to store information like Session ID, user preferences or even login details of a user.

Client-side scripts have no direct impact on server-side information. However, there are still loopholes in site security using DOM (Document Object Model) manipulation to change form values ​​or redirect form actions to submit submitted data on attacker's website.

XSS Attack Impact

Damage due to an XSS vulnerability attack can be diversified when it occurs in a web application. It starts with hijacked user sessions and, when used with social engineering attacks, can lead to the loss of sensitive user data. With XSS attack exploits, attackers can impersonate victims and take over their accounts.

Prevent XSS Attacks

There are several steps and strategies that website owners can use to prevent XSS attacks. Some of them are:

1. Site Security Analysis

To prevent XSS attacks, website owners can even use website vulnerability scanners such as Sucuri or VirusTotal to analyze site security. This helps website owners find out complete audit information about the security vulnerabilities and vulnerabilities present on their site. It also ensures that their website is safe and trusted.

2. Adding SDL

SDL stands for Security Development Lifecycle. Adding SDL in web applications can limit the number of coding errors and security breaches.

This helps developers build highly secure software, including guarding against XSS attacks. SDL assumes that all data received by web applications comes from untrusted sources, even if the data comes from users who have logged in multiple times.

3. Adopt Crossing Boundaries Policy

Crossing boundaries policy allows authenticated users to re-enter their login information before granting users access to certain pages and services on the website.

Even if the user is an authenticated person and has a cookie that allows them to log in automatically. Website owners can reset and ask users to enter their login credentials on certain web pages.

The crossing boundaries policy can be extended further so that sessions are terminated automatically if two IP addresses share the same session data.

4. Using the Correct Meta Tags

Using the meta tags given below reduces the various examples of XSS script injection that may occur.

<META http-equiv="Content-Type" content="text/html; charset= ISO-8859-1">


So what is an XSS attack? XSS is an attack that has the potential to be one of the most dangerous attacks that occur on websites. This could be a consequence that any owner would probably not accept. People can prevent XSS attacks on their websites by performing the steps discussed in this article.

Hopefully, this article about What is XSS (Cross-Site Scripting) Attack?, gives you a little insight. Also, read an article about Where is settings in Windows 10? Get 12 ways to access it that you may need to know. Thank you.

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