In November 2018, security researchers from Check Point made an intriguing discovery about the highly popular game Fortnite. They found that the website was vulnerable to cross-site scripting (XSS) attacks. Due to an outdated, unsecured webpage, hackers could gain unauthorized access to users’ accounts, in-game currency, and audio recording features—all without needing the users’ login credentials.
Cross-site scripting attacks often make headlines when large; well-known companies are targeted. However, businesses of all sizes can fall victim to this cyberattack. XSS attacks were among the most common web attack methods in 2021.
If cybercriminals can easily breach large companies and cause significant damage with a cross-site scripting attack, imagine the problems they could create for your small business. Therefore, it’s more important than ever for small business owners to proactively secure their websites and protect their customers.
What Is a Cross-Site Scripting (XSS) Attack?
When cybercriminals execute cross-site scripting (XSS) attacks, they inject malicious code into a website through form fields or other user input areas to target its users. Once the user’s web browser processes this code, attackers can hijack sessions, secretly track session data, steal sensitive information, or even display spam content on a legitimate website. These attacks can compromise user trust and damage a brand’s reputation, leading to customer loss.
Nearly 75% of websites have vulnerabilities to cross-site scripting attacks. This statistic is particularly alarming for small business owners, given the significant damage an XSS attack can cause, including financial losses and legal repercussions.
The Consequences of Cross-Site Scripting (XSS) Attacks
Cybercriminals often leverage cross-site scripting (XSS) attacks to steal sensitive information, such as session cookies. By doing so, they can hijack a victim’s browser session, enabling them to post on social media, initiate bank transfers, or make purchases on e-commerce websites—all without the user’s knowledge.
What makes XSS attacks particularly harmful is their direct impact on users. If your website is found to have XSS vulnerabilities that allow attackers to compromise customer data, it can severely damage your business’s reputation. Research shows that 65% of users who experience data theft online will not return to the affected website. Additionally, companies may face legal repercussions, financial penalties, and loss of trust, making it imperative to address XSS vulnerabilities promptly.
Possible Results
These are just some of the many potential consequences of a cross-site scripting attack:
- Website downtime
- Theft of user accounts
- Theft of credit card numbers and passwords
- Theft of session cookies
- Theft of users’ files
- Manipulation of files
- Loss of trust in the business
- Creation of fake login pages
- Fake posts that redirect to malicious sites
- Installation of malware on users’ computers
Given that even a single vulnerability can significantly impact your business, it is crucial to take immediate action to prevent cross-site scripting attacks.
4. Effective Ways to Prevent Cross-Site Scripting (XSS) Attacks
The primary cause of cross-site scripting (XSS) attacks is outdated software, including content management system core files, plugins, and themes. Input fields, often overlooked, are another weak point, especially in small businesses that don’t have dedicated security teams to ensure the correct level of protection.
Cybercriminals know that small businesses are especially vulnerable, with an estimated 43% of cyberattacks now targeting them. To avoid falling victim to such an attack, adopt proactive measures and safeguard your website using the following four effective techniques to prevent cross-site scripting attacks and ensure long-term security for your business and customers
1. Keep Your Software Updated
Cybercriminals and developers are constantly in an arms race—attackers relentlessly seek security vulnerabilities while developers work to fix them. If you’re not diligent about updating your software or applications, you leave the door open for cybercriminals to exploit known vulnerabilities.
Review your systems and web applications regularly to ensure they’re current. Additionally, remove unnecessary applications as an extra security measure. Conducting periodic reviews of your remaining applications will help ensure that no vulnerabilities remain for attackers to exploit.
2.Sanitize Input Fields to Prevent XSS Attacks
Input fields are a common entry point for cross-site scripting (XSS) attacks. Sanitizing an input field — or validating that the data is in the correct format — ensures that only expected content is submitted by your visitors, preventing malicious scripts from being injected. You can reduce the risk of an attack by predefining acceptable input (e.g., allowing only numbers, hyphens, and parentheses for a phone number and excluding special characters). To protect your site visitors, it’s essential to sanitize all input fields regularly. Additionally, secure coding practices should be used to safely handle user-generated content, and automated tools should be implemented to help detect and block malicious input in real time.
3. Use Client- and Server-side Form Validation
Validating form submissions is essential to protect your website from malicious inputs that could lead to security vulnerabilities. Client-side validation checks the data on the user’s browser before it is submitted, helping to catch apparent errors or invalid data early. However, relying solely on client-side validation is insufficient, as it can be bypassed.
Server-side validation serves as an extra layer of defense by rechecking the data once it reaches the server. It ensures that even if the client-side validation is bypassed, the server will still reject harmful or malformed data, preventing security issues like cross-site scripting (XSS) attacks.
4. Implement a Web Application Firewall (WAF)
As cyberattacks become more advanced and frequent, using a Web Application Firewall (WAF) to filter out bad bots and other malicious content from your website is essential. Think of a WAF as the gatekeeper to your site, stopping attacks before they can be executed. When selecting a WAF, choose a provider that defends against the latest and most common types of attacks.
With cyberattacks on the rise, taking proactive steps to prevent XSS attacks can make a significant difference. By implementing the above measures, you’re committed to protecting company and customer data, which will pay off in the long term.
Learn how SiteLock can help secure your website today.
Monique Becenti is a product and channel marketing specialist at SiteLock, a cloud-based website security provider protecting over 12 million websites globally. Monique is dedicated to improving the customer experience. SiteLock’s blend of in-depth research, development efforts, aggressive product roadmaps, and access to a vast global data set makes it a leading innovator in web security.