Pierluigi Paganini March 16, 2014

Security experts at Rapid7 firm have public disclosed a series of flaws affecting several thousands of critical infrastructure using Yokogawa software.

Several thousands of critical infrastructure may still be vulnerable to SCADA flaws public disclosed this week. It has been estimated that more than 7,600 different chemicals, power and petrochemical plants are affected by the bugs disclosed by security researcher at Rapid 7 in Yokogawa Electric’s CENTUM CS3000 R3 product. The Windows software affected by the flaws designed by Yokogawa was on the market since 1998 and is largely diffused within the European and Asian infrastructure, including power plants, airports and similar facilities. All of the bugs affect CENTUM CS 3000 software used for industrial control systems. The security expert at Rapid7, Juan Vazquez, and independent security researcher Julian Vilas Diaz discovered the bugs and presented their findings in a talk “Kicking SCADA Around” last weekend at the RootedCON conference in Madrid, Spain successively they published a blog post including technical details about three vulnerabilities. The flaw discovered by the researchers are buffer overflows, heap based and stack based, that could be exploited by attackers to sabotage the Yokogawa application. The first flaw discovered by researchers allows DoS and the execution of arbitrary code with system privileges just sending specially crafted packets to BKCLogSvr.exe to trigger a heap based buffer overflow.

The second vulnerability is quite similar to the previous one, sending a specially crafted packet to BKHOdeq.exe is possible to cause a stack based buffer overflow, allowing “execution of arbitrary code with the privileges of the CENTUM user.” The third vulnerability is a stack based buffer overflow, which affect the BKBCopyD.exe service, could allow the execution of arbitrary code. “The vulnerabilities have been found in the version R3.08.50:

• R7-2013-19.1 – BKCLogSvr.exe Heap Based Buffer Overflow: The “BKCLogSvr.exe” service, started automatically with the system, listens by default on UDP/52302. By sending a specially sequence of packets to UDP/52302 it’s possible to trigger a heap based buffer overflow, after an usage of uninitialized data, which allows to DoS the “BKCLogSvr.exe”, and on last instance, could allow execution of arbitrary code with SYSTEM privileges.
• R7-2013-19.3 – BKHOdeq.exe Stack Based Buffer Overflow: The “BKHOdeq.exe” service, started when running the “FCS / Test Function” listens by default on TCP/20109, TCP/20171 and UDP/1240. By sending a specially crafted packet to the port TCP/20171 it’s possible to trigger a stack based buffer overflow which allows execution of arbitrary code with the privileges of the CENTUM user.
• R7-2013-19.4 – BKBCopyD.exe Stack Based Buffer Overflow: The Yokogawa Centum CS3000 solution uses different services in order to provide all its functionality. The “BKBCopyD.exe” service, started when running the “FCS / Test Function”, listens by default on TCP/20111. By sending a specially crafted packet to the port TCP/20111 it’s possible to trigger a stack based buffer overflow which allows execution of arbitrary code with the privileges of the CENTUM user.“

Rapid 7 firms ethically disclosed the vulnerabilities to Japanese Yokogawa firm back in December, only last week its experts published an advisory on the vulnerabilities. The Japanese Yokogawa invites its customers who use CENTUM CS 300 to immediately update to the latest version of the application (R3.09.50) and patching it to resolve the vulnerabilities.

Pierluigi Paganini

(Security Affairs – SCADA, Yokogawa, Critical infrastructure)