Tag Archive for: access control lists

Tales from the Trenches: Network Backdoors — Lions, and Tigers, and Bears…

Today’s tale from the trench is brought to you by Brad Schwab, Senior Security Solutions Consultant.

One of the greatest concerns for professionals in Network and Security Operations is the potential existence of a backdoor in their network—let alone the presence of numerous backdoors! Identifying backdoors can be a daunting challenge, as they might exist beyond the confines of the configured routing table or take a longer path than the optimized routing path typically followed by traffic. Consequently, conventional traffic mapping tools seldom uncover the presence of a backdoor.

RedSeal is unique in its ability to identify and display all paths through a network, regardless of routing protocols and network address translation (NAT)—therefore exposing all potential backdoors.

While working with a power generation company that managed many extremely remote renewable energy sites, I performed RedSeal data collections on network device configurations across the organization, including company headquarters. From there, I began to perform RedSeal data collections on the power generation farms networks. With this data, I was able to model their network and gain visibility into all the access across their network fabric.

Once all data was collected, we initiated an examination of access vectors into the local generating networks. While engaged in this process, one individual began discussing how the heightened global threat levels had prompted the implementation of a company policy mandating a firewall at each site. This measure aims to safeguard Operational Technology (OT) devices and SCADA Systems. SCADA (Supervisory Control and Data Acquisition) is a software application used for controlling industrial processes by gathering real-time data from remote locations to control equipment and conditions.

As we began verifying that access controls were in place, we concluded there were indeed firewalls present with Access Control Lists (ACLs) blocking and filter inbound traffic. However, because RedSeal shows ALL access vectors, we also noticed that each generation site had two available paths to the internal network—one controlled and limited by the firewall and another that was wide open through the on-site router — a backdoor!

Through RedSeal’s security methodology of “Discover, Investigate, Act” we were able to uncover the backdoors and found that though we started with a small sample of sites, we now knew what to look for and each one had backdoors into the power generation network.

During our investigation we discovered that the secondary wide open access had been set in the case of a site lockout on the firewall. I have seen networks set up like this in the past, although not quite at this scale. It is not terribly uncommon in remote locations to set up a backdoor enabling remote access – however, we learned that with this set up even a firmware upgrade would cause problems. I explained how RedSeal could help verify changes before deployment and then verify implementation with ongoing monitoring for the entire generating network to ensure all sites were always in compliance and no backdoors were in place.  I like to think of it as an always on, always up-to-date audit.  Thus, avoiding any “negative compliance drift” between yearly scheduled audits.

In summary, RedSeal was able to show all the paths through the network—not just the ones that traffic is currently traveling on.  For each path of interest, in this case the backdoors, RedSeal shows every device along the path (hops), and all the ports and protocols that are available for traffic to transit.  Finally, such access can be monitored on an ongoing basis to ensure it does not stray from company policy.

At RedSeal, we’re committed to helping you fortify your digital infrastructure, for good. We proactively help visualize your network, identify attack paths, prioritize risk, and help you stay in compliance to ensure your business and customers stay secure.

Reach out to RedSeal or schedule a demo today.