Many businesses store sensitive customer data in back-end databases that can be accessed through web applications. A WAF can protect against these types of vulnerabilities and prevent data leakage.
Most WAFs also offer detailed monitoring and logging capabilities. They can also block and rate-limit incoming traffic that may indicate common attacks like SQL injection or cross-site scripting.
What is a WAF?
A web application firewall (WAF) is a network security solution that monitors bi-directional web-based traffic to identify and block malicious activity. It’s deployed before business-critical web applications to safeguard them from zero-day exploits and other advanced threats that traditional network firewall technology, intrusion detection systems (IDS), or intrusion prevention systems (IPS) cannot detect.
A Web Application Firewall (WAF) operates at the application layer of the OSI model. It inspects HTTP and Hypertext Transfer Protocol Secure (HTTPS) traffic to filter out malicious requests from an attacker’s computer to damage a company’s infrastructure or steal sensitive data. A WAF protects against common attacks, including cross-site scripting (XSS) attacks, distributed denial-of-service (DDoS) attacks, and SQL injection attacks.
The security technologies inside a WAF work with a set of policies created by the company to define what type of activity is acceptable. This activity is compared to the WAF’s vulnerability database, and any malicious traffic is blocked. WAFs can monitor incoming and outgoing traffic to prevent malware infections or DDoS attacks from spreading to other machines in the network.
WAFs can be delivered as software, on-premises appliances, or a cloud-based technology managed through a single interface. They can be configured to fit the security needs of an individual web application or group of applications. They can also be customized to address new vulnerabilities that are identified.
A hosted WAF is an excellent alternative to an on-premises or appliance-based WAF because it eliminates the need for hardware appliances, reduces costs, and simplifies the management of firewall technology. It’s also more scalable than traditional network firewalls and offers advanced protection like DDoS mitigation, bot defense, and application attack signatures to help businesses keep up with evolving threats. It also eliminates the challenges associated with change control, patch management, and coordinating outage windows that come with managing an on-premises NGFW appliance. Lastly, a unified solution delivers consistent policies wherever users connect. The result is a faster, more agile, more cost-effective way to protect the enterprise from cyberattacks.
What is a Firewall?
Firewalls protect businesses from a wide range of threats. They operate at the network level and offer protection at a higher layer in the OSI (Open Systems Interconnection) model, such as packet filtering, stateful inspection, proxy, and next-generation firewalls (NGFW).
Web application firewall solutions monitor HTTP and HTTPS traffic to protect web applications and sites from malicious activity by monitoring activities at the application layer in the OSI model. They help to protect against web attacks such as cross-site scripting (XSS), distributed denial-of-service (DDoS), and SQL injection attacks.
To do so, WAFs can detect various security threats by examining the contents of each incoming data packet and looking at headers and the content of each request to determine what kind of threat it is. They also use different methods to screen incoming requests, such as delisting and safelists. Safelisting denies all traffic unless included on a list of approved IP addresses. This method is less resource-intensive but could result in the firewall blocking benign traffic. Denylisting is more resource-intensive because the firewall analyzes each incoming packet to determine whether it meets a particular set of criteria.
As a software solution, WAFs can be run either on the same server as the web application or on a separate machine in a shared network on a host-based model (as with open-source firewalls like ModSecurity). There are also cloud-based WAFs that are instances on a per-customer basis and charged in a pay-as-you-go model.
In addition to preventing these attacks, WAFs can protect against other risks, such as remote file inclusion and local file injection. These threats exploit vulnerabilities in a web application by downloading and executing a remote file from outside the web server or injecting code into an existing locally stored file. They can be used to compromise servers, steal information, and take over networks, all of which threaten business productivity.
However, it is common for WAFs to issue increasing alerts because of the difficulty in determining legitimate versus malicious traffic and effectively tuning policies. As a result, security teams may experience alert fatigue and stop tuning the WAF, exposing the application to more significant threats.
What is the difference between the two?
It is essential to grasp the WAF vs firewall difference even though both security technologies can be quite crucial for enterprises. A web application firewall (WAF), a Layer 7 security solution, prevents SQL injection, DDoS, and cross-site scripting. On the other hand, a firewall is an essential element of a cybersecurity strategy that protects network layers 3-7 from unwanted traffic and threats.
A WAF analyzes HTTP requests for patterns that indicate malicious activity and blocks or flag them accordingly. It can include exploring a request’s headers, query strings, and body. A WAF can also block specific IP addresses or hostnames to limit access to the web server from a single source.
WAFs are valuable to any business using web applications and storing private customer data. They help prevent breaches that can damage a company’s reputation and lead to costly fines from regulatory agencies. Using a WAF with other security tools and malware protection helps businesses strengthen their defenses against cyber attacks.
To be effective, a WAF must be configured according to the needs of each business. It should be tailored to meet the unique security requirements of a specific organization, and its settings should be tested and adjusted regularly. It will ensure that the WAF is thwarting attackers while not blocking legitimate traffic and causing other problems for the business.
A business with a customer database must configure the WAF to protect against cross-site scripting and SQL injection, common causes of database breaches. Exposing sensitive information during cyber attacks can harm a business’s customers, eroding their trust and resulting in significant revenue losses.
A WAF can be built into a server-side software plugin or hardware appliance or offered as a cloud service to filter web traffic and protect against attacks. A WAF should be configured to match the security needs of a particular organization, and it can be supplemented with additional tools like NGFWs to create a robust cybersecurity solution.
Which is better for your business?
WAFs are crucial components of a comprehensive security strategy for companies that rely on web applications with high-value data or operations. Often, these applications house sensitive customer data and are targeted by attackers seeking to steal that information. WAFs protect these apps by blocking known attack patterns and vulnerabilities. The WAF also filters traffic at OSI Layer 7 to ensure users meet security conditions before accessing a web application.
When it comes to selecting a WAF, there are many options available. IT teams can install WAFs on hardware appliances or software-based systems that run as server plugins. Some more advanced WAF solutions offer security-as-a-service in the cloud. Host-based WAFs require installation on network hosts, which can add to overall system complexity and overhead costs. These systems are typically easier to configure and manage than other types of WAFs but can still require additional staff resources to deploy and maintain.
Traditional on-premises WAFs operate using a positive security model that allows traffic to pass only if it meets pre-approved rules. These rules are typically built based on top web app security vulnerabilities identified by the Open Web Application Security Project (OWASP). Because of this, these WAFs can often result in false positives that block legitimate traffic and cause performance issues for users.
Next-generation, or stateful WAFs, are more agile and take a more contextual view of web application traffic. It allows them to ward off more complex attacks that attempt to bypass security controls by blending in with real traffic. For example, these newer WAFs can detect evasion tactics like DNS spoofing that attackers use to mask malicious activity.
Other features offered by some WAFs include API security, SSL/TLS offloading, and data loss prevention. The latter part helps prevent sensitive data from leaving a business network, which can help reduce data theft and improve compliance with regulations. Additionally, some WAFs offer rate limiting, which helps prevent denial-of-service attacks or brute-force login attempts.
While WAFs and firewalls are helpful security tools, they are not interchangeable. Just as you wouldn’t equip a police car with fire extinguishers, you must select the suitable device for your business needs. For this reason, many enterprises turn to comprehensive security platforms like NGFWs that combine the capabilities of WAFs and firewalls into one centrally managed system.
