Three Advisories Published – 04-16-19

Yesterday the DHS NCCIC-ICS published two control system security advisories for products from WAGO and Delta Industrial Automation, and one for PLC products from multiple vendors.

PLC Advisory

This advisory describes an uncontrolled resource consumption vulnerability in specific PLC products from ABB, Phoenix Contact, Schneider Electric, Siemens, WAGO. The vulnerability was reported by Matthias Niedermaier (Hochschule Augsburg), Jan-Ole Malchow (Freie Universität Berlin), and Florian Fischer (Hochschule Augsburg). The responses range from a firmware update from Schneider, to ‘its not really a vulnerability but here are generic workarounds’, to ‘its not a vulnerability’ from Siemens. There is no indication that the researchers have been provided an opportunity to verify the efficacy of the fixes.

NCCIC-ICS reports that a relatively low-skilled attacker could use a publicly available exploit to emotely influence configured cycle times.

NOTE: The Schneider advisory referenced in this advisory was released in February and listed a 2018 CVE number for the reported vulnerability. Neither CVE number is currently available.

WAGO Advisory

This advisory describes a hard-coded credential vulnerability in the WAGO Series 750-88x and 750-87x PLCs. The vulnerability was reported by Jörn Schneeweisz of Recurity Labs. WAGO has new firmware that mitigates the vulnerability. There is no indication that Schneeweisz has been provided an opportunity to verify the efficacy of the fix.

NCCIC-ICS reports that a relatively low-skilled attacker could remotely exploit this vulnerability to change the settings or alter the programming of the device.

NOTE: I briefly mentioned this vulnerability last Saturday.

Delta Advisory

This advisory describes three vulnerabilities in the Delta Industrial Automation CNCSoft screen editor software. The vulnerabilities were reported by Natnael Samson and an anonymous researcher via the Zero Day Initiative. Delta has an updated version that mitigates the vulnerabilities. There is no indication that the researchers have been provided an opportunity to verify the efficacy of the fix.

The three reported vulnerabilities are:

• Stack-based buffer overflow - CVE-2019-10947;

• Heap-based buffer overflow - CVE-2019-10951; and

• Out-of-bounds read - CVE-2019-10949

NCCIC-ICS reports that a relatively low-skilled attacker with uncharacterized access could exploit this vulnerability to cause buffer overflow conditions that may allow information disclosure, remote code execution, or crash the application.

Public ICS Disclosures – Week of 02-09-19

This week we have five vendor disclosures for products from Kunbus, Schneider (3) and Rockwell; five vendor updates from Siemens; one coordinated disclosure for products from Resource Data Management and one exploit for a previously disclosed vulnerability for products from AVEVA.

Kunbus Advisory

Kunbus published an advisory for five vulnerabilities in its KUNBUS-GW Modbus TCP PR100088 product. The vulnerabilities were reported by Nicolas Merle of Applied Risk. Kunbus is working on an update to mitigate the vulnerabilities.

The five reported vulnerabilities are:

• Conditional authentication bypass;

• Missing authentication for critical function;

• Denial of service;

• Publication of information by parameter data in an HTTP GET request; and

• Plain text storage of passwords

Schneider Advisories

Schneider has published an advisory describing six vulnerabilities in its Sarix Enhanced and Spectra Enhanced cameras. The vulnerabilities were reported by Deng Yongkai (NSFOCUS) and Gjoko Krstic (Zero Science). Schneider has a new firmware version that mitigates the vulnerabilities. There is no indication that the researchers have been provided an opportunity to verify the efficacy of the fix.

The six reported vulnerabilities are:

• A permissions, privileges, and access control vulnerability - CVE-2018-7816;

• A command injection vulnerability (2) - CVE-2018-7825 and CVE-2018-7826;

• A cross-site scripting (XSS) vulnerability (2) - CVE-2018-7827 and CVE-2018-7828; and

• An improper neutralization of special elements in query vulnerability - CVE-2018-7829

Schneider has published an advisory describing a buffer error vulnerability in its Vijeo Designer Lite software. The vulnerability is self-reported. Schneider has provided generic mitigations as the product has reached end-of-life status.

Schneider has published an advisory describing three vulnerabilities in its  Modicon M221 and

SoMachine Basic products. The vulnerabilities were reported by Matthias Niedermaier (Hochschule Augsburg), Jan-Ole Malchow (Freie Universität Berlin), Florian Fischer (Hochschule Augsburg) and Reid Wightman (Dragos Inc.). Schneider has updates available to mitigate the vulnerabilities. There is no indication that the researchers have been provided an opportunity to verify the efficacy of the fix.

The three reported vulnerabilities are:

• An environment vulnerability (2) - CVE-2018-7821 and CVE-2018-7823; and

• An incorrect default permissions vulnerability - CVE-2018-7822

Rockwell Advisory

Rockwell has published an advisory describing two vulnerabilities in its PowerMonitor 1000 monitor that were publicly reported (with exploits) in December (here and here) by Luca Chiou. Rockwell has provided generic mitigation measures pending development of updates. It also provides a link to intrusion prevention system (by CheckPoint) rules to detect the cross-site scripting vulnerability.

The two reported vulnerabilities are:

• Cross-site scripting - CVE-2019-19615; and

• Authentication bypass - CVE-2019-19616

 Siemens Updates

Siemens published an update for their advisory on Spectre and Meltdown Vulnerabilities in Industrial Products. They added updated affected version data and provided links to mitigations for:

• SIMATIC ET 200 SP Open Controller; and

• SIMATIC IPC547E

NOTE: NCCIC-ICS updated their alert (ICS-ALERT-18-011-01) for this vulnerability when Siemens added a new advisory. That technically included this update since the link provided in the alert goes to the latest version of the Siemens advisory.

Siemens published an update for their advisory on Spectre-NG (Variants 3a and 4) Vulnerabilities in Industrial Products. They added updated version data and provided links to mitigations for:

• SIMATIC ET 200 SP Open Controller:

• SIMATIC ET 200 SP Open Controller (F);

• SIMATIC S7-1500 Software Controller;

• SIMATIC IPC547E;

• SIMATIC ITP1000;

• SIMATIC IPC3000 SMART V2;

• SIMATIC IPC347E;

• SIMATIC HMI Basic; and

• Panels 2nd Generation:

They also removed the following unaffected products from the advisory:

• SIMATIC IPC227E;

• SIMATIC IPC277E;

• SIMATIC IPC327E; and

• SIMATIC IPC377E

NOTE: NCCIC-ICS is expected to update their advisory.

Siemens published an update for their advisory on Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP. They added two additional vulnerabilities to the list for these products:

• CVE-2018-1000876; and

• CVE-2018-16862

NOTE: NCCIC-ICS has not published an advisory/alert on these vulnerabilities.

Siemens has published an update for their advisory on Denial-of-Service in SICAM A8000 Series. They updated the CVSS vector due to known exploit.

Siemens has published an update for their advisory on Foreshadow / L1 Terminal Fault Vulnerabilities in Industrial Products. They updated the affected version data and provided links to the mitigation measures for:

• SIMATIC IPC547E;

• SIMATIC IPC547G;

• SIMATIC ITP1000;

• SIMATIC IPC3000 SMART V2; and

• SIMATIC IPC347E

They also removed the following unaffected products from the advisory:

• SIMATIC IPC227E;

• SIMATIC IPC277E;

• SIMATIC IPC327E; and

• SIMATIC IPC377E

NOTE: NCCIC-ICS has not published an advisory/alert on these vulnerabilities.

Resource Data Management

Safety Detective published an article describing default credential vulnerabilities for commercial refrigeration systems from Resource Data Management. The article describes how the researchers were able to locate vulnerable systems, change settings, and manipulate controls in systems in hospitals and stores.

AVEVA Exploit

Jacob Baines published an exploit for vulnerabilities in the AVEVA InduSoft Web Studio. The vulnerabilities were reported by NCCIC-ICS earlier this month.

Public ICS Disclosures – Week of 08-11-18

This week we have three vendor disclosures from Yokogawa (2), and Belden and an advisory update from Siemens. There are also two disclosures from vdeCERT for products from Phoenix Contact and WAGO. Both of those disclosures pointed to an interesting research paper on “Measuring PLC Cycle Times under Attacks”.

Vnet/IP Network Switches Advisory

Yokogawa reports a debug vulnerability in their Vnet/IP network switches. The vulnerability is due to a third-party software issue (see Belden below). Yokogawa reports a work around since there “is no provision of firmware’s which are countermeasures against this vulnerability”.

License Management Advisory

Yokogawa reports a buffer overflow vulnerability in the license management function in a number of their products. Yokogawa has an update that mitigates the vulnerability. The advisory notes that ICS-CERT has been notified so there is a strong chance that this will be reported by ICS-CERT in the coming week.

Belden Advisory

Belden reports (.PDF Download) 16 separate vulnerabilities in the TCPdump functionality of their OWL industrial routers and HiOS ethernet switches. Belden provides a work around and notes that the TCPdump functionality is inactive by default.

NOTE: This advisory is actually dated July 27^th, 2018 (and outside of this week’s window), but because of its relation to the Yokogawa advisory it is being included here because of the potential for other vendors being affected. Also note that the CVE’s for the vulnerabilities date back to 2016 and 2017. That indicates that either it took a long time to figure out the minor workaround, or Belden was not really concerned about these vulnerabilities.

Siemens Update

Siemens updated their general customer advisory for the Spectre/Meltdown vulnerabilities. The advisory was last updated on July 17^th, 2018.This update adds information on the L1 Terminal Fault / Foreshadow versions of the vulnerabilities.

NOTE: The latest version (update H) of the ICS-CERT alert on Spectre/Meltdown still does not mention the newer variants of the vulnerabilities reported in this Siemens advisory.

Phoenix Contact Advisory

VDE-CERT reports an uncontrolled resource consumption vulnerability in the Phoenix Contact ILC 1x1 ETH. The vulnerability was reported by Matthias Niedermaier (Hochschule Augsburg), Jan-Ole Malchow (Freie Universität Berlin) and Florian Fischer (Hochschule Augsburg). A generic workaround has been provided.

WAGO Advisory

VDE-CERT reports an uncontrolled resource consumption vulnerability in the WAGO 750-8xx Controllers. he vulnerability was reported by Matthias Niedermaier (Hochschule Augsburg), Jan-Ole Malchow (Freie Universität Berlin) and Florian Fischer (Hochschule Augsburg). A generic workaround has been provided.

Measuring PLC Cycle Times under Attacks

The research paper that pointed out the Phoenix Contact and WAGO vulnerabilities discussed above provides an interesting look at the possibility of detecting on-going control-system attacks by monitoring PLC cycle times. As an academic look at this potential attack detection technique, this paper is well worth reading. From a process chemist’s point of view this points out a specific, unintended process problem, that these attacks might pose that also provide an indication of an on-going cyber-attack.

One of the problems that a process engineer/chemist has to deal with in designing a control system scheme in the chemical industry (and that is probably true for other industries as well) is the lag time between when a process indicator (sensor) notes that a process state needs to be changed and when the process actuator (valve for example) can complete its action to effect that change. A great deal of effort goes into ‘tuning’ the system to minimize the potential adverse impacts caused by that time lag.

This paper notes that a variety of attacks can affect the lag time within the PLC. Normally, this portion of the total lag time is small and nearly constant, so it is essentially ignored in the tuning process. This paper notes that in some attacks the lag time can be increased by up to several seconds (this can be an eternity in critical portions of many chemical reactions). To make things even more interesting it appears that TCPdump attacks (like those discussed in the Yokogawa and Belden advisories above) can actually speed-up the PLC processing and decrease the overall lag time, creating a whole new set of process problems.

This means that certain types of process upsets can be an indication of on-going cyber-attacks on control systems. To say the least, this complicates the job of the process overseers (another root cause possibility that needs to be examined), but it could provide control systems engineers with a warning to check their systems for other signs of attacks.