Attack of the XSS
X marks the spot...
3 min read
It is an older problem, but we must know it because we are the effect of our causes. and our causes lie in history. And so studying history is merely studying the self. Today we have XSS to learn.
Cross-Site Scripting (XSS) is a type of cyber attack that involves injecting malicious code into a website or web application usually in the forms. This code is typically executed in the client-side browser and is designed to manipulate the behavior or appearance of the site or to steal sensitive information from the user.
There are three main types of XSS attacks:
- DOM-based XSS: This type of attack involves manipulating the Document Object Model (DOM) of a web page, rather than injecting code directly into the page. This can allow the attacker to bypass client-side input validation and execute malicious code in the user's browser. XSS attacks can be highly effective, as they can leverage the trust that a user has in a particular website or web application. They can also be difficult to prevent, as they often involve finding and exploiting subtle vulnerabilities in the website or web application's code. This can happen when the website does not properly sanitize user input, allowing the attacker to inject malicious code into the page.
- Reflected XSS: This type of attack involves injecting malicious code into a website through a URL or form input, which is then reflected back to the user. For example, an attacker might send a victim a link to a website with malicious code embedded in the URL. When the victim clicks on the link, the website will reflect the malicious code back to the victim's browser, which will execute the code. This type of attack relies on the victim's willingness to click on a link or submit a form with malicious input.
- Stored XSS: This type of attack involves injecting malicious code into a website or web application and storing it in a persistent manner, such as in a database. For example, an attacker might leave a comment on a blog post with malicious code embedded in it. Every time someone reads the blog post, the malicious code will be executed in their browser. This type of attack can potentially affect all users who visit the site, not just the victim who initially clicked on the malicious link.
These can also be difficult to prevent, as they often involve finding and exploiting subtle vulnerabilities in a website or web application's code unless sanitized.
What is the sanitization of Data in the context of XSS?
Sanitization of data refers to the filtering and modifying user input to remove or escape potentially harmful characters or code.
This is an important security measure that can help to prevent cross-site scripting (XSS) attacks by ensuring that user input is safe to be displayed on a website or web application.
There are several ways to sanitize data to prevent XSS attacks, including:
Escaping special characters: This involves replacing special characters, such as
>, with their HTML entity counterparts, such as
>. This can prevent the browser from interpreting the special characters as HTML tags and executing any malicious code that might be contained within them.
Stripping HTML tags: This involves removing any HTML tags that are contained in user input. This can help to prevent attackers from injecting malicious code into a website or web application through user input.
Validating input: This involves checking user input to ensure that it conforms to a set of predetermined rules. For example, a website might only allow users to submit alphanumeric characters in a form field and reject any input that contains special characters or HTML tags.
Sanitizing user input is an important security measure that can help to prevent XSS attacks and other types of cyber threats. It is important to regularly review and update your data sanitization processes to ensure that they are effective at preventing attacks. You never know when you are in someone's cross-hairs.