In the course of performing hundreds of risk and PCI assessments, we occasionally comecomputer-1895383_1280-1.jpg across a client who is running an obsolete version of a system, application, or device. Normally, when a system has reached “end-of-life,” it is no longer supported. On the surface, this would appear to be a security risk and also a violation of PCI DSS requirement 6.1: “Ensure that all system components and software are protected from known vulnerabilities by having the latest vendor-supplied security patches installed. Install critical security patches within one month of release.” Organizations must determine the ideal strategy to address risk associated with using obsolete systems/applications. Short of replacing/upgrading the offending system, there may be more creative means to offset this risk.

There is no one-size-fits-all solution, but here are some potential arrows for your risk-based-approach quiver:

  • Are there any compensating controls that would effectively eliminate risk associated by not patching (since systems can no longer be patched)? This may include host-based intrusion prevention, white-listing, real time monitoring of processes and critical files, etc.
  • Are there any Third Parties who provide extended support for the end-of-life product?
  • What risks are associated with the end-of-life product? Are there any publicly known vulnerabilities? If there are no known vulnerabilities associated with an end-of-life product, it may still be “reasonably secure” …. today. But, unlike supported systems/applications which will provide you with a ‘fix’ once a vulnerability is known, the unsupported systems force you to walk the tightrope without a net. What is secure today may have a vulnerability tomorrow. Consider:
    • What can be done to monitor/search for recently disclosed vulnerabilities pertaining to the end-of-life platform. You will need to be extremely diligent in keeping an ear to the track to watch for vulnerabilities associated with that product/system/application and have established processes in place to stay on top of this.
    • If possible, risk can be mitigated by segregating unpatchable systems from other critical systems through firewalls and access control lists (ACLs) to strictly control traffic. 
    • Consider implementing host-based intrusion prevention (HIPS), in-line IPS, in-line proxies, or security gateways.
    • Understand what entities can access the system or application in question and lock down those that require access. Also consider beefing up the access controls (such as multi-factor authentication) in general.
    • Lock down what the system can do to allow only critical processes needed for running the system and security controls.
    • Monitor, monitor, monitor – in addition to file integrity monitoring (FIM), consider implementing controls to monitor all running processes to prevent or alert your team on any unauthorized ones. Also make sure that the system/application is effectively monitored by your centralized monitoring systems.
    • Consider performing additional testing to demonstrate that the overall risk associated with a particular vulnerability/obsolete platform has been mitigated (a penetration test for example).

If you do find yourself in a situation where part of your critical environment has reached its end-of-life and your organization may be in violation of PCI DSS requirement 6.1, do the legwork to understand the risk associated with the end-of-life system/application as well as evolving threat landscape. It is possible to prolong the ‘afterlife’ of these systems/applications if you take a thorough, pragmatic, risk-based approach which, in turn, may dramatically reduce risk, alleviate headaches, and help save time and money. If you are unsure whether you are running the most current versions of a system, application, or device, feel free to contact me directly.

Contact Steve Levinson

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