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AUSCERT External Security Bulletin Redistribution
ICS Advisory (icsa-20-105-06) Siemens SIMOTICS, Desigo, APOGEE, and TALON
13 January 2021
AusCERT Security Bulletin Summary
Product: Siemens SIMOTICS
Operating System: Network Appliance
Impact/Access: Overwrite Arbitrary Files -- Remote/Unauthenticated
Denial of Service -- Remote/Unauthenticated
CVE Names: CVE-2019-13939
Revision History: January 13 2021: Updated products affected
April 15 2020: Initial Release
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ICS Advisory (ICSA-20-105-06)
Siemens SIMOTICS, Desigo, APOGEE, and TALON (Update A)
Original release date: January 12, 2021
All information products included in https://us-cert.cisa.gov/ics are provided
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(DHS) does not provide any warranties of any kind regarding any information
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1. EXECUTIVE SUMMARY
o CVSS v3 7.1
o ATTENTION: Exploitable from an adjacent network/low skill level to exploit
o Vendor: Siemens
o Equipment: SIMOTICS, Desigo, APOGEE, and TALON
o Vulnerability: Business Logic Errors
2. UPDATE INFORMATION
This updated advisory is a follow-up to the original advisory titled
ICSA-20-105-06 Siemens SIMOTICS, Desigo, APOGEE, and TALON that was published
April 14, 2020, to the ICS webpage on us-cert.cisa.gov.
3. RISK EVALUATION
Successful exploitation of this vulnerability could allow an attacker to affect
the availability and integrity of the device.
4. TECHNICAL DETAILS
4.1 AFFECTED PRODUCTS
Siemens reports the vulnerability affects the following products and versions:
o APOGEE MEC/MBC/PXC (P2): All versions prior to 2.8.2
o APOGEE PXC Series (BACnet): All versions, 3.0 and newer
o APOGEE PCX Series (P2): All versions, 2.8.2 and newer
- --------- Begin Update A Part 1 of 2 ---------
o Desigo PXC (Power PC): All versions, 2.3x to v6.00.327
o Desigo PXM20 (Power PC): All versions, 2.3x to v6.00.327
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o Desigo PXC (Power PC): All versions, 2.3x and newer
o Desigo PXM20 (Power PC): All versions, 2.3x and newer
o SIMOTICS CONNECT 400: All versions prior to 0.3.0.330
o TALON TC Series (BACnet): All versions, 3.0 and newer
4.2 VULNERABILITY OVERVIEW
4.2.1 BUSINESS LOGIC ERRORS CWE-840
The affected products could allow an attacker to change the IP address of the
device to an invalid value. This may allow an attacker to make device
configuration changes and affect its availability.
CVE-2019-13939 has been assigned to this vulnerability. A CVSS v3 base score of
7.1 has been assigned; the CVSS vector string is ( AV:A/AC:L/PR:N/UI:N/S:U/C:N/
o CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Energy,
Food and Agriculture, Water and Wastewater Systems
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
Siemens reported this vulnerability to CISA.
Siemens recommends the following mitigations and workarounds for the following
o Disable the DHCP client and use static IP address configuration instead
(Note that the DHCP client is disabled by default on APOGEE/TALON and
o APOGEE MEC, MBC, PXC: Use static IP address configuration.
o APOGEE PXC Series, TALON TC Series, and Desigo products: If using static IP
address is not possible, please contact a Siemens support office.
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o Desigo PXC (Power PC): Update to v6.00.327 (login required)
o Desigo PXM20 (Power PC): Update to v6.00.327 (login required)
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o SIMOTICS CONNECT 400: Update to v0.3.0.330
As a general security measure Siemens strongly recommends users protect network
access to affected products with appropriate mechanisms. Users are advised to
follow recommended security practices in order to run the devices in a
protected IT environment. Additional information on industrial security by
Siemens can be found at: https://www.siemens.com/industrialsecurity .
For more information see Siemens Security Advisory SSA-162506
CISA recommends users take defensive measures to minimize the risk of
exploitation of this vulnerability. Specifically, users should:
o Minimize network exposure for all control system devices and/or systems,
and ensure that they are not accessible from the Internet .
o Locate control system networks and remote devices behind firewalls, and
isolate them from the business network.
o When remote access is required, use secure methods, such as Virtual Private
Networks (VPNs), recognizing that VPNs may have vulnerabilities and should
be updated to the most current version available. Also recognize that VPN
is only as secure as the connected devices.
CISA reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices
on the ICS webpage on us-cert.cisa.gov . Several recommended practices are
available for reading and download, including Improving Industrial Control
Systems Cybersecurity with Defense-in-Depth Strategies .
Additional mitigation guidance and recommended practices are publicly available
on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Organizations observing any suspected malicious activity should follow their
established internal procedures and report their findings to CISA for tracking
and correlation against other incidents.
No known public exploits specifically target this vulnerability.
For any questions related to this report, please contact the CISA at:
Toll Free: 1-888-282-0870
CISA continuously strives to improve its products and services. You can help by
choosing one of the links below to provide feedback about this product.
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