What is Cross-Site Scripting (XSS)?

Cross-Site Scripting, referred to as XSS, is a kind of security flaw that frequently appears in web applications. When malicious scripts are injected into web pages that other users view, XSS attacks result. Although HTML or VBScript are other acceptable scripting languages, JavaScript is the most common language used to write these scripts.

Moreover, XSS is a web security vulnerability that permits unauthorised individuals to compromise user interactions within a vulnerable app by injecting malicious codes.

Types of XSS Attacks

1. Reflected XSS: The malicious script from this tactic stems from the existing HTTP request. In this attack, the script is reflected off a web server. The attacker creates a hostile URL containing the script and lures the victim into clicking on it. When the victim accesses the link, the server brings in the compromised script in the response, which is then executed by the victim’s browser.
2. Stored XSS: Attackers resource the malicious script from the website’s database. In this attack, the malicious script is permanently saved on the target server, such as in a database. When a user requests the affected web page, the server incorporates the malicious script and legitimate content, and the user’s browser can execute the script.
3. DOM-Based XSS: The vulnerability lies in client-side rather than server-side code. This type of XSS attack occurs when the web application’s client-side script modifies the DOM (Document Object Model) unsafely, enabling an unauthorised entity to inject a malicious payload into the DOM environment, which is then executed by the victim’s browser.

Types of Exploitation

1. Impersonation: Attackers can impersonate or masquerade as the victim user.
2. Action Execution: They can carry out any actions the user can perform.
3. Data Access: Accessing any data the user can reach.
4. Credential Theft: Capturing user login credentials.
5. Defacement: Virtual defacement of the website.
6. Trojan Injection: Injection of trojan functionality into the website.

Impact of XSS Vulnerabilities

1. Brochureware Application: Minimal impact in applications where users are anonymous and all information is public.
2. Sensitive Data Applications: Significant impact in applications holding sensitive information like banking transactions, emails, or healthcare records.
3. Elevated Privileges: Critical impact if the compromised user has elevated privileges within the application, potentially allowing full control over the vulnerable application and compromising all users and their data.

XSS attacks can have adverse consequences, including the theft of sensitive information like cookies, session tokens, or personal data, defacing websites, redirecting users to malicious websites, or even executing unauthorised actions on behalf of the user. 

How can iZOOlogic help my Company or Organisation?

Find out how iZOOlogic can protect you against Cross-Site Scripting (XSS) attacks with the Web App Threat Protection solutions.

To find out more about how iZOOlogic can help protect your company’s cyber security, schedule a demo.