Cross-Site Scripting (XSS): How to secure your website from the attack?

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Nowadays you can do everything online and we see even the oldest professions in the world modernize and move to the Web. So with the online enablement of several of new services we see Application security turn more imperative.

Developers follow professional app development standards and various kind of testing such as manual code review, automated testing, unit testing, integration testing and various others are done, however the malicious code and scripts still succeed in getting inside the application.

The renowned attacker that has majorly troubled the developers is Cross-Site Scripting (XSS). Though it’s not new but for the novice developers, it could be. So let’s explore XSS.


What is Cross-Site Scripting (XSS)?

Well, Cross-Site Scripting comes around as a threat manipulating the client-side code of web application owing to the security flaws of client-side scripting languages, such as HTML and JavaScript. XSS allows hackers to infuse malicious client-side script in a website that’s executed by the users. XSS leads to change in the presentation of data in an unauthorized manner and it directs the browser to incorrect page and website automatically.

An attacker won’t target a victim directly by leveraging XSS but instead it’s going to exploit vulnerability within a website or web application that the victim is going to visit. So basically it uses the vulnerable website as a vehicle to deliver a malicious script to the victim’s browser.

What leads to XSS attacks?

It has been analyzed that sites suffer XSS attacks due to its requirement to be interactive, accepting and returning data from users. Thus attackers can also have direct interaction with an application’s processes, pass data designed to subterfuge as legitimate application requests or commands via usual request channels like scripts, URLs and form data. This kind of communication that takes place at the application layer exploits inadequately written applications so that they can bypass traditional perimeter security defences.

A WhiteHat Security Statistics Report of 2008 says that 90% of the websites have one vulnerability at the minimum while 70% of them are XSS-related.

The types of XSS Attacks:

Persistent: In case of persistent attacks, the malicious code is sent to a website where it’s stored for particular time such as – message board posts, web mail messages, web chat software and a lot more. The web application is affected simply as it views the web page where vulnerable code/link is sent.

Non-persistent: Here the attacker is certain to send victim an email that contains link with malicious content (JavaScript) and the link is clicked by victim, the HTTP Post request is initiated from the victim’s browser and then it’s sent to the vulnerable app automatically.

Afterwards, the malicious JavaScript is shown in victim’s browser executing in the content of the victim’s user’s session.

DOM Based: In this kind of XSS attack, the data doesn’t appear on the web server and it reflects on the JavaScript code on the client side.

So this is how the attacks take place on the websites in various ways. The hackers can easily run malicious JavaScript code in a victim’s browser and they just require to look for a way to inject a metadata or messages that are used by the users to visit a web page and this is easy to be identified with social engineering tools being at handy.

As the user visits a vulnerable page that has an injected JavaScript code, the attackers requires including user input in web pages and it’s there a string is inserted and it’s seen as a code by the victim’s browser. The malicious script of the attacker is executed with the page loading in victim’s browser in no time.

How to find if your website is vulnerable to Cross-site Scripting?

XSS vulnerabilities are the most common kind of vulnerabilities out there on the internet. However, the good thing is that you can easily run a test to find out if your website or web applications are vulnerable to XSS and other vulnerabilities by running an automated web vulnerability scan with the use of Vulnerability Scanner offered by various of website and web applications development companies.

So what can be done to prevent XSS attacks and remove this vulnerability from the web applications?

Now that you have realized the huge impact of XSS, it must be on your mind to look for ways to protect from this malware. Well, no worry as there is a way out. You CAN disable these worms fooling you and making your website vulnerable with the use of HttpOnly flag. The HP Fortify tool work wonders and is used by the developers scanning the web applications at the places where code is endangered with the attack of malwares such as XSS. This way the tool engages the points next to description where the code is susceptible to get attacked as well as it offers the processes to fix the security holes. At Octal Info Solution, we offer the most efficient and effective web and mobile application development services to the clients all around the world at cost-effective prices. Start building robust and scalable websites using advanced technology and tools.

Arun Goyal

Arun Goyal is Founder-CEO at Octal Info Solution Technology innovation and trends insight come easy to Arun with his thorough knowledge in the domain. A leader in his own rights, his grad-friends see him as an avid researcher and a technology evangelist. See him talking about ideas, trends and technology as a part-time author to this blog. Follow him on Twitter, Facebook, LinkedIn and go through his ideas on distinct topics.

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