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AUSCERT External Security Bulletin Redistribution
ICS Advisory (ICSA-20-105-07) Siemens SCALANCE & SIMATIC
13 January 2021
AusCERT Security Bulletin Summary
Product: Siemens SCALANCE
Operating System: Network Appliance
Impact/Access: Denial of Service -- Remote/Unauthenticated
CVE Names: CVE-2019-19301
Revision History: January 13 2021: Updated products affected and mitigation details
April 17 2020: Initial Release
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ICS Advisory (ICSA-20-105-07)
Siemens SCALANCE & SIMATIC (Update C)
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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is governed by the Traffic Light Protocol (TLP) marking in the header. For more
information about TLP, see https://us-cert.cisa.gov/tlp/ .
1. EXECUTIVE SUMMARY
o CVSS v3 7.5
o ATTENTION: Exploitable remotely/low skill level to exploit
o Vendor: Siemens
o Equipment: SCALANCE, SIMATIC
o Vulnerability: Resource Exhaustion
2. UPDATE INFORMATION
This updated advisory is a follow-up to the advisory update titled
ICSA-20-105-07 Siemens SCALANCE & SIMATIC (Update B) that was published
September 8, 2020, to the ICS webpage on us-cert.cisa.gov.
3. RISK EVALUATION
Successful exploitation of this vulnerability can result in a denial-of-service
4. TECHNICAL DETAILS
4.1 AFFECTED PRODUCTS
The following versions of SCALANCE are affected:
o SCALANCE X-200 switch family (incl. SIPLUS NET variants): all versions
o SCALANCE X-200IRT switch family (incl. SIPLUS NET variants): all versions
o SCALANCE X-300 switch family (incl. X408 and SIPLUS NET variants): all
- --------- Begin Update C Part 1 of 2 ---------
o [S: SCALANCE S602: all versions :S]
o [S: SCALANCE S612: all versions :S]
o [S: SCALANCE S623: all versions :S]
o [S: SCALANCE S627-2M: all versions :S]
- --------- End Update C Part 1 of 2 ---------
The following versions of SIMATIC are affected:
o SIMATIC CP 443-1 (incl. SIPLUS NET variants): all versions
o SIMATIC CP 443-1 Advanced (incl. SIPLUS NET variants): all versions
o SIMATIC RF180C: all versions
o SIMATIC RF182C: all versions
4.2 VULNERABILITY OVERVIEW
4.2.1 UNCONTROLLED RESOURCE CONSUMPTION ('RESOURCE EXHAUSTION') CWE-400
The VxWorks-based Profinet TCP stack can be forced to make resource-intense
calls for every incoming packet, which can lead to a denial-of-service
CVE-2019-19301 has been assigned to this vulnerability. A CVSS v3 base score of
7.5 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/
o CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
Siemens has identified the following specific workarounds and mitigations users
can apply to reduce the risk:
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o [S: For SCALANCE S-600 family (S602, S612, S623, S627-2M): migrate to a
successor product within the SCALANCE SC-600 family, v2.1 or later version.
For details refer to the notice of discontinuation . :S]
- --------- End Update C Part 2 of 2 ---------
o For SIMATIC RF180C and RF182C: migrate to a successor product within the
SIMATIC RF18xC/CI family v1.3 or later version.
For details refer to the notice of discontinuation .
o In all other cases please follow the General Security Recommendations.
Additional information on industrial security by Siemens can be found at:
For further inquiries on security vulnerabilities in Siemens products and
solutions, please contact Siemens ProductCERT .
For more information on this vulnerability, please see Siemens security
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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