SCADA Vulnerabilities & Exposures (SVE)

CRITIFENCE® SCADA Vulnerabilities and Exposures Database (SVE)

[SVE-614342347] Beckhoff Embedded PC Images and TwinCAT Components Vulnerabilities

Date Type Platform Author EDB-ID CVE-ID OSVDB-ID Download App SIS Signature
2016-10-04PLCBeckhoff Embedded PC, TwinCATMarko Schuba N/A2014-5414, 2014-5415N/AN/AN/A

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# Beckhoff Embedded PC Images and TwinCAT Components Vulnerabilities
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### OVERVIEW

Marko Schuba from FH Aachen University of Applied Sciences has identified vulnerabilities in Beckhoff's Embedded PC Images and TwinCAT Components. He published them and reported them to Beckhoff afterward. In 2014, Beckhoff produced a new build and security advisories with instructions to mitigate these vulnerabilities.

These vulnerabilities could be exploited remotely.




### AFFECTED PRODUCTS

Beckhoff reports that the vulnerabilities may affect the following products:

* All Beckhoff Embedded PC Images with a creation date prior to October 22, 2014, and
* All TwinCAT Components featuring Automation Device Specification (ADS) communication.






### IMPACT

If used without proper protection, an attacker may misuse those services to gain unauthorized access to systems or read and manipulate transmitted information, especially passwords. Attackers may use ADS protocol to rapidly probe a large number of user or password combinations.

Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of these vulnerabilities based on their operational environment, architecture, and product implementation.





### BACKGROUND

Beckhoff is a German-based company.

Beckhoff Embedded PCs are hardware PC products meant to be installed in control cabinets and be configured to function in many different ways in an industrial control system. Beckhoff TwinCAT is a software product that can allow a PC to function as a real-time controller. According to Beckhoff, these products are deployed across several sectors including Critical Manufacturing, Energy, and Water and Wastewater Systems, and others. Beckhoff estimates that these products are used worldwide.





### VULNERABILITY CHARACTERIZATION


# VULNERABILITY OVERVIEW


IMPROPER RESTRICTION OF EXCESSIVE AUTHENTICATION ATTEMPTS

Attackers may use ADS protocol to rapidly probe a large number of user or password combinations.
CVE-2014-5414 has been assigned to this vulnerability. A CVSS v3 base score of 9.1 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N).




EXPOSED DANGEROUS METHOD OR FUNCTION

In versions older than October 22, 2014, Beckhoff Images for Embedded PCs are delivered with the Windows CE Remote Configuration Tool reachable, enabled CE Remote Display service, and enabled telnet service. Use of these services is recommended only in trusted networks. If used without proper protection, an attacker may misuse those services to gain unauthorized access to systems or read and manipulate transmitted information, especially passwords. Precondition of the exploitation of those services is that the attacker has access to the services at the corresponding network ports (TCP 80/987/23). This implies that the services are running.
CVE-2014-5415 has been assigned to this vulnerability. A CVSS v3 base score of 9.1 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N).






### VULNERABILITY DETAILS


# EXPLOITABILITY

These vulnerabilities could be exploited remotely.


# EXISTENCE OF EXPLOIT

No known public exploits specifically target these vulnerabilities.


# DIFFICULTY

An attacker with a low skill would be able to exploit these vulnerabilities.





### MITIGATION

Beckhoff recommends in their IPC Security Manual (https://download.beckhoff.com/download/Document/ipc/industrial-pc/ipc_security_en.pdf) to use network and software firewalls to block all network ports except the ones that are needed. 

Beckhoff also recommends that default passwords be changed during commissioning before connecting systems to the network.

In their advisories (Advisory 2014-001,g Advisory 2014-002,h Advisory 2014-003,i which were published November 17, 2014) for these issues, Beckhoff also recommends the following mitigation solutions:

* Update images to build October 22, 2014, or newer, which solve these problems by disabling the services by default.

* Disable the Windows CE Remote Configuration Tool by deleting the subtree "/remoteadmin." The configuration of the web server paths can be found in the Windows registry at the path "HKEY_LOCAL_MACHINE\COMM\HTTPD\VROOTS\."

* Disable startup of CE Remote Display service (cerdisp.exe) with deleting the registry key containing the "CeRDisp.exe" [-HKEY_LOCAL_MACHINE\init\Launch90].

* Disable telnet by setting the registry key [HKEY_LOCAL_MACHINE\Services\TELNETD\Flags] to dword: 4

* Restrict ADS communication to trusted networks only.