Content Delivery Network Security Considerations

Today, countless businesses and individuals alike are using content delivery networks (CDNs) to deliver and receive content, respectively. According to industry research, global CDN traffic has grown dramatically over the past decade, driven by streaming, cloud applications, and eCommerce.

This rapid growth positions CDNs as prime targets for cybercriminals intent on intercepting, altering, and stealing crucial information. Security should be a core part of any CDN strategy. So what does CDN security actually involve, and what risks arise when it’s misconfigured or missing? This article outlines the key security considerations every organization should understand.

What is CDN security?

CDN security refers to the measures and technologies used to protect a content delivery network (CDN) and the content it delivers. A CDN is a network of servers that work together to distribute web content quickly. It allows for the quick transfer of assets needed for loading Internet content, including HTML pages, JavaScript files, stylesheets, images, and videos. Because CDNs sit directly between users and origin servers, securing this layer helps prevent attacks, protect data in transit, and ensure content is delivered safely and reliably.

Is a CDN the same as a web host?

No, a CDN is not the same as a web host, although they both play crucial roles in delivering web content to users and involve the use of data centers. A web host provides a server, typically located in a data center, where your website's data is stored and managed. It's where your website 'lives' on the internet. When a user wants to visit your website, their browser requests data from your web hosting server at the data center.

On the other hand, a CDN is a network of web servers distributed globally across multiple data centers, designed to deliver your website's content more efficiently. The CDN caches a copy of your website's static content (like images, CSS, JavaScript) on servers in these data centers around the world. When a user visits your website, the CDN routes this content from the server closest to them, located in one of the data centers. This proximity reduces the distance the data travels, improving loading times and reducing bandwidth costs.

What are the security concerns of a CDN?

While CDNs improve performance and availability, security risks can still arise if they are not properly configured or paired with the right protections.

• Bad bots and automated abuse: Basic CDN caching alone may not block malicious bots. Without additional controls, attackers can scrape content, probe for vulnerabilities, or attempt credential abuse.

• Cached data exposure: If sensitive content is cached improperly or access controls are misconfigured, private data such as user information could be exposed to unauthorized users and used for account compromise or extortion.

• DDoS attacks: Distributed denial-of-service attacks remain one of the most serious CDN security concerns, as they overwhelm servers with high traffic and can take content offline.

• Origin server bypass: Attackers may attempt to target the origin server directly if access controls are weak, bypassing the protections provided at the CDN layer.

• Misconfiguration and access control gaps: Poor role-based access control (RBAC), weak authentication, or missing IP restrictions can allow unauthorized changes to CDN settings or content.

• Limited monitoring and visibility: Without centralized logging and traffic monitoring, suspicious activity and emerging threats may go undetected until damage has already occurred.

When configured with protections such as Web Application Firewalls (WAFs), DDoS mitigation, strong access controls, and continuous monitoring, CDNs significantly improve website security. Without these measures, the risks above can leave even high-performance content delivery networks exposed.

Why is security especially important for eCommerce?

Here's why CDN security is especially important for eCommerce:

• Safeguard Data: eCommerce platforms often handle sensitive customer data, including personal information and credit card details. CDN security helps protect this data from breaches and unauthorized access in real-time.

• Performance and Availability: CDNs improve website performance by caching content close to the user. Ensuring CDN security means that this performance is maintained, which is crucial for eCommerce platforms where page load times can significantly impact sales.

• Trust and Reputation: A secure CDN helps maintain the integrity and availability of your eCommerce site. Security breaches or extended downtime can damage a company’s reputation and lead to a loss of customer trust.

• Compliance with Regulations: eCommerce sites are often subject to regulations like GDPR, PCI DSS, etc. CDN security helps support compliance with these regulations, avoiding potential legal issues and fines.

• Protection Against Malware and Vulnerabilities: A CDN can provide an additional layer of security when paired with firewalls and other solutions to protect against malware and other vulnerabilities.

• Secure Content Delivery: Encryption and secure access controls ensure that content is securely delivered to the end-user, preventing man-in-the-middle attacks.

CDN security best practices

Though CDNs bring inherent security risks, they’re still a necessity for any website owner looking to help deliver users a seamless experience. But just because website owners use CDNs, that doesn’t mean websites need to be left vulnerable to cybercriminals. In fact, there are steps you can take to ensure that employing a fast, robust CDN won’t compromise the security of your website and its content.

1. Choose a reputable CDN service

There are a number of CDN providers available on the market, each of varying quality. Get in contact with someone representing a CDN before committing to it as an option—and don’t be afraid to ask tough questions. For example, you should know how frequently the CDN will cache your data and how often the CDN provider conducts comprehensive penetration testing to ensure a server is secure.

You should also understand what happens in the event that your server fails and what you—and your CDN provider—are able to do about it. For example, are there existing failover security measures in place to switch to a backup server in the event of an outage? If an outage occurs without proper failover, your site may become unavailable, disrupting service and potentially bypassing performance and protection layers.

All told, carefully choosing the CDN provider that’s right for you helps eliminate numerous CDN security concerns.

2. Use a web application firewall

Alone, basic CDN caching does not provide full protection, which is why a web application firewall (WAF) is recommended. WAFs act as a barrier between your content and the broader internet. They’re able to monitor and block any and all HTTP(s) traffic exhibiting security red flags, while seamlessly allowing access to legitimate website traffic.

3. Enable SSL/TLS encryption

Combining a CDN with SSL/TLS encryption fortifies your online presence. By leveraging a CDN's distributed servers to optimize content delivery and ensure compatibility with SSL/TLS encryption protocols, you establish a secure and efficient transfer of data. This tandem approach not only improves latency but also safeguards sensitive information, bolstering trust and reliability for visitors.

4. Implement strong access protocols

Establishing strong access policies is a key mitigation strategy in cybersecurity, ensuring only authorized users can access CDN management consoles and origin infrastructure. This involves deploying multi-factor authentication (MFA) for more robust user verification and adopting role-based access control (RBAC) to restrict access in line with job functions.

Regular audits and timely updates of access protocols are crucial for mitigating vulnerabilities and maintaining system integrity. These measures help protect CDN settings, cached content, and backend systems while reducing the risk of unauthorized changes, data exposure, and service disruption.

5. Keep software up-to-date

Software updates often include patches for security flaws that could be exploited by attackers to gain unauthorized access or disrupt service. By regularly updating software (including server operating systems, content management systems, and web applications that sit behind the CDN), organizations can protect against the latest known threats, ensuring the integrity and availability of the content being delivered. Additionally, updates can bring performance improvements and new security features, enhancing overall efficiency.

6. Enable DDoS protection

Use built-in CDN protections or third-party mitigation services to absorb and filter large volumes of malicious traffic before it overwhelms your servers or takes your site offline.

7. Secure your origin servers

Restrict direct access to origin infrastructure, authenticate edge-to-origin traffic, and ensure attackers cannot bypass the CDN to target backend systems directly.

8. Configure secure HTTP headers (CSP, HSTS)

Use the CDN to enforce Content Security Policy (CSP) and HTTP Strict Transport Security (HSTS) consistently. These help to reduce data leakage, prevent content injection, and enforce encrypted connections.

9. Apply geo-blocking where appropriate

Restrict or filter traffic based on geographic regions to reduce exposure to region-specific threats and unauthorized access.

10. Conduct regular security audits

Perform ongoing reviews of CDN configurations, access controls, and certificates to identify weaknesses, correct misconfigurations, and maintain a strong security posture.

Partner with SiteLock for CDN security

Nobody wants to browse an unsecured website. If you’re looking to sustain and grow your traffic by providing a fast, reliable, and secure browsing experience, CDN security should be part of your strategy. SiteLock’s content delivery network helps improve performance while protecting your site with built-in DDoS mitigation and web application firewall protection.

By following the steps above and using a security-focused CDN, you can provide a user experience that’s not just fast but protected at every layer. And if your site is compromised, reach out to SiteLock immediately and ask about our hacked website repair services. Or, review our website security pricing and plans for more information.