A search engine that indexes servers and other internet devices is helping hackers to find industrial control systems that are vulnerable to tampering, the US Computer Emergency Readiness Team has warned.
The year-old site known as Shodan makes it easy to locate internet-facing SCADA, or supervisory control and data acquisition, systems used to control equipment at gasoline refineries, power plants and other industrial facilities. As white-hat hacker and Errata Security CEO Robert Graham explains, the search engine can also be used to identify systems with known vulnerabilities.
According to the Industrial Control Systems division of US CERT, that's exactly what some people are doing to discover poorly configured SCADA gear.
“The identified systems range from stand-alone workstation applications to larger wide area network (WAN) configurations connecting remote facilities to central monitoring systems,” the group wrote in an advisory (PDF) published on Thursday. “These systems have been found to be readily accessible from the internet and with tools, such as Shodan, the resources required to identify them has been greatly reduced.”
Besides opening up industrial systems to attacks that target unpatched vulnerabilities, the information provided by Shodan makes networks more vulnerable to brute-force attacks on passwords, many of which may still use factory defaults, CERT warned. The organization advised admins to tighten security by:
- Placing all control systems assets behind firewalls, separated from the business network
- Deploying secure remote access methods such as Virtual Private Networks (VPNs) for remote access
- Removing, disabling, or renaming any default system accounts (where possible)
- Implementing account lockout policies to reduce the risk from brute forcing attempts
- Implementing policies requiring the use of strong passwords
- Monitoring the creation of administrator level accounts by third-party vendors
Short for Sentient Hyper-Optimized Data Access Network, Shodan contains a wealth of information about routers, servers, load balancers and other hardware attached to the internet. Its database was built by indexing metadata contained in the headers the hardware broadcasts to other devices. Searches can be filtered by port, hostname and country. In other words, not only can it identify a Solaris server, it can in many cases identify a Solaris server located in Pakistan that remains vulnerable to a known exploit.
CERT's warning comes a few month after reports that a worm called Stuxnet burrowed into SCADA systems controlling nuclear power plants. The attack, which many researchers speculate was intended to disrupt Iran's nuclear aspirations, demonstrated the success in which determined hackers have in penetrating control systems. ®