Firewalls are the first line of defence for malicious information passing through a network. It is a very component in network security. However, like all security measures, the firewall depends on human error or lack thereof along with its configuration. To make sure the firewalls are working effectively, there must be regular Firewall Auditing so that the administrators can understand the working of the firewall better and also to make changes to it if required. Standards such as SOX, PCI-DSS and HIPAA, NERC have recently ensured a growing requirement for firewall audits. Other than these,however, firewall audits are important to catch the loopholes in your security and to know where the correction needs to be done. Over time due to the advancement in technology, there are always more and more threats to our security. This also results in various different configurations of the firewall to combat these threats.
Frequent and detailed firewall audits are essential to decrease the risks. A typical firewall audit scenario includes the following steps:
- Define network access policy – This basically encompasses the security requirements
- Know your firewall configuration – This is essential to understand the weak points and to build network interfaces or Access Control List(ACL)
- Analyze the firewall against access policy – Review the rules of security policy against the ACL to find loopholes or violations
- Find redundant or unused rules and make changes – Rules that are rarely used or ones that cancel out others are not recommended in a firewall
In order to keep up with all the network connectivity requirements, the firewall of an organization must be changed or updated very frequently, a minimum of once or twice a month. These changes or modifications are because of either business needs or to strengthen the security of the firewall in place. These modifications require careful planning, analysis, approval, effective execution and monitoring.
Firewall Auditing can be done either manually or automatically. Though firewall auditing is extremely important, conducting manual audits in an organization is a hassle and will raise quite a few challenges. A single firewall audit takes days of work depending on the complexity of its configuration. Manual auditing is thus very slow. It is also quite expensive as compared to automated auditing. Human error is also a major factor in the case of manual auditing and even the smallest of mistakes can leave a huge loophole in the security of the firewall. Hence manual auditing is not a viable option. Therefore the only route to achieving the aim of low firewall management cost and lower risks for the organization is to automate the auditing.
The benefits of this are plenty. Some include:
- Lesser time
- Fewer security risks due to automated assessment
- Less expensive
- Firewalls last longer due to optimization of performance
Thus to maintain an effective and proper firewall audit program, organizations must define the network access policies along with the configuration of the firewall and the ACL. Regular assessment makes sure that the risks are lower and also that the firewall lasts longer.