A WAF is a software, an appliance or a service that analyzes HTTP conversations via a ruleset to detect malicious packets and prevent them from reaching your web servers. This can reduce downtime, data theft and help meet compliance requirements. Unlike network firewall solutions, WAFs specifically protect against web-based threats like SQL injection and cross-site scripting (XSS).
Cookie Poisoning
A cookie poisoning attack aims to manipulate, forge or intercept data stored in cookies on a user’s computer. This can steal identifying information, gain access to a web application, or bypass security features. A WAF is designed to protect against such attacks by analyzing HTTP traffic at the application layer and continuously checking for suspicious patterns.
A WAF can be deployed in a whitelist model that only lets in known good traffic or a blacklist model that blocks malicious traffic. It inspects HTTP/S requests and server responses, looking for web application vulnerabilities like cookie manipulation, SQL injection, file inclusion, cross-site scripting, and command and control (C&C) communication. WAFs operate at OSI model layer 7, protecting against attacks targeting web applications and servers.
A WAF can be deployed using a rule-based approach, where organizations painstakingly define their own rules to detect and block malicious traffic. However, this requires extensive maintenance and can be challenged by new attacks and changing threat vectors. Some NGFWs can load threat intelligence and automatically reconfigure rules to stay up-to-date. They can also act as SSL termination proxies to inspect incoming and outgoing encrypted traffic and prevent SSL-based attacks. Combined with a WAF vs firewall can provide comprehensive protection against threats that target the application layer.
SQL Injection
A SQL injection attack attempts to compromise a web application by injecting SQL code into an input field. It’s a common security threat that can result in sensitive data leaks, denial of service and even data theft. This is why it’s important to have your sensitive information encrypted to ensure its confidentiality and protect it from unauthorized access.
A web application firewall protects website applications and APIs from vulnerabilities by filtering incoming traffic and blocking malicious attempts to access web servers. In addition to examining HTTP(s) requests, the WAF may also analyze the content of those requests, using techniques like sanitization, signature detection and IP reputation to identify suspicious traffic and block it.
While a WAF can be standalone, deploying it with an NGFW is best. These two firewalls complement each other, with the NGFW protecting the network perimeter and the WAF focused on web applications.
Traditionally, a WAF operates through rules, either provided out of the box by the vendor or customized and configured by the organization deploying it. While this approach has its merits, it’s prone to false positives and requires high maintenance as new attacks emerge.
A modern WAF solution will be able to offer automated protection that reduces the need for manual intervention and provides a more accurate picture of normal application behavior. It includes an auto-learning engine that analyzes incoming application traffic and uses it to build a model of normal behavior. Then, it compares that to incoming request patterns and identifies anomalies or malicious behavior based on the results.
Cross-Site Scripting
The web application firewall (WAF) works at the HTTP layer to protect web applications and servers from advanced cyberattacks. It detects and blocks web application attacks, including XSS, SQL injection and DDoS. By preventing such attacks, WAFs protect businesses’ data and help them meet compliance requirements such as PCI DSS.
A WAF identifies threats by intercepting and analyzing traffic and using an engine that can detect malicious patterns in incoming requests, such as cookie manipulation and advanced HTTP DDoS attacks. WAFs often use correlation engines to analyze incoming requests and triage them using known attack signatures, AI/ML analysis, application profiling or custom security rules to decide whether a request should be blocked.
WAFs can be deployed on-premises or in a cloud environment, depending on the business’s needs. Some are even hosted by providers, which provide comprehensive protection against all types of threats, from DDoS attack mitigation to SSL decryption and protocol validation.
Network firewalls are critical to any cybersecurity strategy, as they serve as protective buffers between a private network and the broader internet. However, as digital innovation advances rapidly, businesses need additional protection against advanced cyberattacks that can infiltrate their systems through vulnerabilities in web apps. They need the combined power of an NGFW and a WAF to avoid these attacks.
Malware
A hacker’s most common weapon is malware, which exploits vulnerable web applications. As attacks against web apps increase, implementing a WAF is increasingly important. The 2020 Verizon Data Breach Investigations Report found that 43% of breaches involved web-based applications.
A WAF analyzes HTTP interactions and reduces or eliminates malicious activity before it reaches the server for processing. It can protect against various threats and vulnerabilities, including SQL injections, cross-site scripting (XSS) and impersonation attacks. It can also mitigate buffer overflows, hotlinking and brute force attacks.
Most WAFs rely on rules to filter out traffic, and these need to be updated regularly to keep up with new vulnerabilities. However, recent advancements in machine learning have enabled some WAFs to update their rules automatically. The main difference between a network firewall and a WAF is that they operate on different network layers. Network firewalls protect the broader network, while WAFs are specifically designed to protect web applications. As the threat landscape changes, it’s becoming more challenging for businesses to find comprehensive solutions. This is leading to the rise of NGFWs, which integrate the capabilities of WAFs and network firewalls in a single system. They offer extra context to security policies and can mitigate advanced threats like ransomware.
