According to Cloudflare, “A WAF or web application firewall helps protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet.” Acting as a layer 7 defense in the OSI model, WAFs safeguard applications from various types of attacks, including cross-site forgery, cross-site scripting (XSS), file inclusion, and SQL injection.
A WAF acts as a shield between the web application and the internet. Unlike a proxy server that protects a client's identity, a WAF functions as a reverse proxy. It ensures that client requests pass through the WAF before reaching the server, protecting it from exposure.
WAFs operate by employing a set of rules known as policies. These policies filter out malicious traffic and protect the application against vulnerabilities. WAFs' flexibility lies in their ability to quickly modify policies, allowing for a swift response to evolving attack vectors.
WAFs can operate based on either a blocklist or an allowlist approach. Blocklist WAFs, or negative security model WAFs, protect against known attacks. On the other hand, allowlist WAFs, or positive security model WAFs, only admit traffic that has been pre-approved.
Both blocklist and allowlist approaches have their advantages and drawbacks. To address this, many WAFs offer a hybrid security model, combining elements of both approaches to provide complete protection.
WAFs can be implemented in three different ways, each with its own benefits and considerations:
Network-based WAFs are typically hardware-based solutions. Installed locally, they minimize latency and offer protection. However, they tend to be the most expensive option since they require the storage and maintenance of physical equipment.
Host-based WAFs are integrated directly into an application's software. This approach is more cost-effective compared to network-based WAFs and offers greater customization. However, host-based WAFs consume local server resources, which can impact performance. Additionally, their implementation complexity and maintenance costs may require engineering expertise.
Cloud-based WAFs provide an affordable and easily implementable alternative. These WAFs are typically a turnkey service requiring a simple DNS change to redirect traffic. Cloud-based WAFs have minimal upfront costs, as users pay for security as a service monthly or annually. However, users must entrust the responsibility to a third party, which may limit their control over certain WAF features.
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Cloud-based WAFs offer several advantages that make them a popular choice for businesses:
A web application firewall (WAF) is a security solution designed to protect web applications by monitoring, filtering, and blocking HTTP/S traffic to and from a web application. In healthcare, WAFs help protect web-based applications that handle sensitive patient information, ensuring the confidentiality, integrity, and availability of protected health information (PHI).
A WAF benefits HIPAA compliance because it helps prevent web-based attacks, such as SQL injection, cross-site scripting (XSS), and other exploits that could compromise PHI. By securing web applications, healthcare organizations can prevent unauthorized access to patient data, mitigate the risk of data breaches, and ensure compliance with HIPAA’s security and privacy requirements.
See also: HIPAA Compliant Email: The Definitive Guide