What are Cloud Firewalls?

A Firewall is a Security Product, whose main function is to filter out unauthorized and malicious traffic and they run between trusted and untrusted networks i.e private networks and the internet. These Firewalls block the malicious network and only allow the authorized traffic to bypass them, this is specified through a set of rules which is configured by the Administrators. 

Cloud Firewall :
A cloud Firewall is nothing but a Firewall that is deployed in the cloud and these cloud Firewalls form a virtual barrier, to prevent malicious network traffic in the cloud, they function as same as traditional Firewalls, but the only difference is the cloud firewall is hosted in a cloud platform. 

Cloud Firewalls act as a security product that acts as a shield and protects from unauthorized network traffic and this protection is provided to different cloud components like Cloud CRM, Cloud Database, Email Cloud.

Need of Cloud Firewall :
Cloud Firewall is very essential in providing security against malicious and unwanted network traffic. Cloud is a source of virtual space which stores a lot of crucial data that belongs to enterprises and there is a great need for Security Mechanism to protect it and as firewalls have been successful in on-premise physical infrastructure.
Cloud Providers configured robust Firewall Environments for the virtual workspaces as well. 

These Cloud Firewalls are designed in such a way that they can block the cyberattacks directed against the virtual cloud workspaces and provide 24/7 security to the cloud components, we can assume these are the same as the security guards that guard banks and these Virtual Workspaces i.e. Cloud servers can be considered as Bank assets. 

Types Of Cloud Firewall : 
Cloud Firewalls are broadly distributed into two types namely : 

1. Next-Generation Firewalls(NGFW)
2. SaaS Firewalls

These are explained as following below.

1. Next-Generation Firewalls (NGFW)  -
These are Cloud Firewall Service that is intended to be deployed in a data center with aim of protecting the Organization's servers Infrastructure-As-a-Service or Platform-as-a-Service Model. In these models, the cloud firewall software is deployed and guards Network Traffic in cloud operations. 

2. SaaS Firewalls -
These kinds of Firewalls are configured in such a way that their main job is to secure the network of the virtual space same as traditional firewalls but the only difference being hosted in the cloud. These have various other names and types like : 

1. Security-as-a-Service -
   This is a Business model used in the IT Industry where the responsibility of providing security services is done by the service provider i.e any third-party consulting company for which the customers subscribe on a monthly or yearly basis according to their requirements.
2. SECaas -
   It provides users with Internet security, providing protection from cyber-attacks and threats such as DDOS which constantly check for access points to compromise websites.
3. Software-as-a-Service(SaaS) -
   Software-as-a-Service is a business delivery model in IT where the software is hosted centrally and users avail it through a valid license, generally SaaS is mainly considered in cloud computing, and these SaaS apps are accessed by users via a thin client such as a web this may contain various kinds of software such as office software, CAD Software, development software, gamification software, banking software, etc.
4. Firewall-as-a-Service (FWaaS) -
   Firewall-as-a-Service to Cloud Firewall Ecosystem hosted on Cloud servers, which delivers Layer 7 capability in Access Management, Identity Management, Filtering of URLs, Advanced Threat Protection, DNS Security, intrusion prevention systems, DNS Security. FWaaS enables organizations with-
   1. Simplification of their IT Infrastructure
   2. Centralized Management from a single console eliminates challenges in patch management
   3. Policy management
   4. Coordinating outage windows across the organization where users coordinated.

Working Of Cloud Firewall :
The working of a cloud firewall is similar to that of a traditional firewall the only difference is the cloud firewall is being hosted in a cloud environment. These Cloud Firewalls function like, packet-scanning firewalls in which they filter out incoming data before its entering the network which involves assessing active connections of the cloud network, based on these connections, the firewall will decide which packets are safe and can be passed through it, hence a typical cloud firewall performs following functions: 

Packet Filtering : 
The small amounts of data in a network are called packets. These packets are exposed to a certain group of filters before they bypass the Firewall in which the packets are scanned against some threats, if they match these threats then the Firewall blocks them from entering the Network. 

Proxy Service :
These Proxy services prevent direct connections between the client's device and incoming packets thereby protecting the network area from unauthorized access. 

Stateful Inspection :
Cloud Firewalls also perform the stateful inspection of incoming packets of data where these firewalls check for some policies between source and destination in order to establish a session between them, if the required policies are not between source and destination then the access will not be provided and the users need to register new policies for them.

Advantages :

1. Deployment and Scalability -
   Cloud Firewalls are easy to scale and deploy owning to their own software nature, these take very little time compared to traditional firewalls to be deployed on the cloud and cause fewer disruptions in business, and are very easy to maintain. Unlike Traditional Firewalls these come with unlimited scale as the bandwidth increases, FWaas adjust to maintain parity hence businesses need not worry about the size of traffic in the network.
2. Access and Identity Management -
   Cloud Firewalls are designed to filter traffic from multiple sources between various tenants and network partitions, hence they can easily distinguish bot and human hence thereby preventing bot attacks, They hold control over access management and authentication to ensure granular control on cloud servers.
3. Updates -
   Firewalls are designed with real-time automatic updates which provide protection against advanced threat filtering systems enabled on Firewalls.
4. Availability -
   Cloud Based Firewalls are available 24/7 which is not possible with the traditional firewalls as the cloud firewalls have in-built redundancies (power, HVAC, network) hence they are prepared for any kind of incidents throughout the day.

Disadvantages :

1. Cloud-Based Firewalls really do not know who the visitor is they blindly scan the packets based on policies created in the Firewall Registry and if the attacker managed to create a fake replica of any existing policies then he can easily cheat the Firewall and bypass into the Cloud Network.
2. Cloud-based firewalls lack the understanding of how a site really functions, what are software-based circumstances, who are authenticated users, and what permissions are needed.
3. As these Firewalls follow generic use cases they may fail in detecting vulnerabilities that are software specific such as Plugin Vulnerabilities.
4. The sites behind the Cloud Firewall are dependent on Firewall Service Provider, if the service is down chances are that it can create an outage in the cloud network.