Friday, August 15, 2014

Remote Access Best Practices

Common wisdom is that “if I have a firewall and encryption, I must be safe.” Virtual private networks (VPNs) are seen as the solution to the remote access problem, but this common belief is very much mistaken. Viruses, malware and online attacks move through encrypted VPN connections as easily as they can move through un-encrypted local area networks (LANs). The whole point of a VPN is to make remote users feel as though they are locally connected to trusted LANs. Encryption provides protection against data theft, data manipulation, and man-in-the-middle attacks, but it provides zero protection against attacks from either the networks they connect, their workstations, or their endpoints. Laptops, workstations and mobile devices used for remote access are notoriously prone to compromise.

Now to be fair, understanding of remote access risks varies greatly. Some utilities very much do “get it” and have deployed powerful remote access protections. The Department of Homeland Security (DHS) Catalog of Control System Security: Recommendations for Standards Developers provides much better advice than just “use a firewall and VPN.” The North American Electric Reliability Corporation (NERC) 2011 Guidance for Secure Interactive Remote Access is even better – in fact, it’s pretty good, as it even starts to mention more advanced and appropriate protections.

One of these more advanced protections are hardware-enforced industrial cyberperimeters, which are Waterfall’s focus. All software has bugs, and some bugs are security vulnerabilities. In practice then, all software is vulnerable. The Heartbleed bug and second set of OpenSSL bugs makes this point in spades. These bugs allowed attackers to steal private security keys from public-key cryptosystems used by a large fraction of the world’s websites, and in fact used by OpenSSL-based VPN implementations, as well. Since the bugs were announced, I have spoken to many experts about them. Not one believes that this vulnerability lay in wait, un-exploited, these last many years. Governments and organized crime rings all over the world have spent billions over the last decade to develop sophisticated attack tools, and to find and exploit zero-day attacks. For example, the latest Wikileaks revelation is that the NSA has a list of vulnerabilities able to compromise pretty much every firewall in existence.

All software is vulnerable. Software protections have failed repeatedly to protect IT networks. Why, then, should we trust software to protect critical control system networks, especially when hardware-based protections are available? Unidirectional Gateways replicate industrial servers for painless, safe and continuous remote monitoring. Remote Screen View lets remote personnel see the screens of critical machines, and participate in emergency problem resolution by directing the actions of local personnel over the phone in real time. Even a simple Secure Bypass device adds enormous value to an emergency VPN capability. No remote user should have the power to initiate a remote connection into a protected, critical network without the knowledge and participation of personnel at the industrial site. And no targeted attacker should have the power to initiate a remote connection to an industrial site simply by attacking software.

Hardware-based remote access protections are more powerful than software-based protections, and are far simpler. Serious software-based protection is not easy at all, and as hard as it is to implement, those protections can never be as thorough as simple hardware-based protections.

The time for hardware-based protections has arrived. Why is everyone still talking about software?

For more information on products for protecting your critical infrastructure site from the Heartbleed vulnerability and other remote access pain points, please click here.

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