Firewall Management Essentials: Quick Wins
As we put a little bow on our Firewall Management Essentials series, it’s time to focus on getting quick value from your investment. We are big fans of a Quick Wins approach, because far too many technologies sputter as deployment lags and value commensurate with the investment is never seen. The quick wins approach focuses on building momentum early in the deployment by balancing what can be done right now against longer-term goals for a technology investment. If a project team doesn’t prove value early and often, that typically dooms the implementation to failure. For firewall management, the lowest hanging fruit is optimization of existing rule sets before implementing a strong change management process. But let’s not put the cart before the horse – first you need to deploy the tool and integrate it with other enterprise systems. Deployment and Integration The good news for firewall management is that one central server can handle quite a few firewalls – especially because the optimization and change management processes happen on a periodic, rather than continuous or real-time, basis. It’s not like management devices need to be inline and monitoring continuously, so the deployment architecture won’t make or break the implementation. Typically you deploy the firewall management server in a central location, and have it discover all the firewalls in your environment. You might kickstart the effort by feeding the list of existing firewalls into the management system. Do you want one central system, or a distributed environment? That depends on the scale of your environment and how quickly you need to be notified of changes. The longer the interval before rechecking each device’s configuration, the longer the window before you detect an unauthorized change. So you need to balance resource consumption against frequent checks to narrow the exploitation window between exploitation and detection. The deployment architecture depends more on the frequency of monitoring for configuration changes than on anything else. The change process (workflow) can run off the central server. And the math to optimize a rule set doesn’t consume resources on a firewall. We have seen large firewall environments (think service providers) managed by a handful of firewall management devices – multiple devices installed for availability and redundancy, rather than for performance reasons. For integration, as described earlier in this series, you will want to pull or push information from tools like a vulnerability management system, a SIEM/log management tool, and/or a reporting/GRC system. Most of these tools have well-established APIs, and it is reasonable to expect your vendor to already have integrated with the leading tools in these categories. Pulling information into the firewall management tool provides more context to understand what changes pose what risk. The area where you will gain the most value from enterprise integration is the help desk/task management system. Given the operational leverage of automating an effective firewall change management process, you will want to make sure changes are tracked in whatever tool(s) the operations team uses so you don’t have two sources of information, and everything is in sync. The good news is that these operational tools are mature, with mature SDKs for integration. Again, it is reasonable to expect your firewall management vendor to have already integrated with your work management environment. Getting the Quick Win and Showing Value We covered the change management process first in this series, because over time it is where we typically see the most sustainable value accrued. But in a quick wins scenario we need to get something done now. So going through existing firewalls and pinpointing areas of improvement, in terms of both security and performance, can yield the quick win we want. This is the optimization process. The first job is to get value, but that is no good unless you can communicate it. So look to reports to highlight the results of the early optimization efforts. You will want to show things like how many unused rules were eliminated (reducing attack surface), as well as whether any of your old rules conflicted, and how the cleanup improved security. This quick effort (it should take a day or two) can build momentum for the next area of focus: change management. Once the change management process is accepted in the environment and enumerated in the firewall management tool, you can start tracking service levels and response times on changes happening daily. You can also track the number of times changes that would have increased attack surface were flagged (and stopped) before going operational, to show how the tool reduces risk and increases the accuracy of firewall changes. This highlights the benefits of a firewall management tools to reduce the risk of a faulty rule change and adding attack surface. A what-if analysis of potential changes can ensure that nothing will break (or crush performance) before actually making a change. You can also demonstrate value by migrating rules from one firewall to another. If you need to support a heterogeneous environment, or are currently moving to a NGFW-based architecture, these tools can provide value by suggesting rule sets based on existing policies and optimizing them for the new platform. If you are a glutton for punishment you can migrate one device without using the tool (busting out your old spreadsheets), and then use the firewall management tool for the next migration for a real comparison. Or you can use an anecdote (we saved XX days by using the tool) to communicate the value of the firewall management tool. Either way, substantiate the value of the tool to your operational process. Finally, at some point after deploying the tool, you will have an assessment or audit. You can then both leverage and quantify the value of the firewall management tool, in terms of saving time and increasing the accuracy of audit documentation. Depending on the regulation, the tool is likely to include a pre-built report which requires minimal customization the first time you go through the audit, in order to generate documentation and substantiate your firewall controls. You have now learned a bit about how to manage your firewalls in a
