Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2022.0181
Advisory (icsa-22-013-03) Siemens Energy PLUSCONTROL
14 January 2022
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Siemens Energy PLUSCONTROL
Publisher: ICS-CERT
Operating System: Network Appliance
Impact/Access: Denial of Service -- Remote/Unauthenticated
Provide Misleading Information -- Remote/Unauthenticated
Access Confidential Data -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2021-31890 CVE-2021-31889 CVE-2021-31885
CVE-2021-31346 CVE-2021-31345 CVE-2021-31344
Reference: ESB-2022.0094
ESB-2021.4289
ESB-2021.3874
Original Bulletin:
https://us-cert.cisa.gov/ics/advisories/icsa-22-013-03
- --------------------------BEGIN INCLUDED TEXT--------------------
ICS Advisory (ICSA-22-013-03)
Siemens Energy PLUSCONTROL
Original release date: January 13, 2022
Legal Notice
All information products included in https://us-cert.cisa.gov/ics are provided
"as is" for informational purposes only. The Department of Homeland Security
(DHS) does not provide any warranties of any kind regarding any information
contained within. DHS does not endorse any commercial product or service,
referenced in this product or otherwise. Further dissemination of this product
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 8.2
o ATTENTION: Exploitable remotely/low attack complexity
o Vendor: Siemens Energy
o Equipment: PLUSCONTROL
o Vulnerabilities: Type Confusion, Improper Validation of Specified Quantity
in Input, Buffer Access with Incorrect Length Value, Integer Underflow,
Improper Handling of Inconsistent Structural Elements
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could result in access to TFTP
memory buffer contents, information leaks, and denial-of-service conditions.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following versions of PLUSCONTROL, a control device for high-power energy
transmission, are affected:
o PLUSCONTROL 1st Gen: All versions
3.2 VULNERABILITY OVERVIEW
3.2.1 ACCESS OF RESOURCE USING INCOMPATIBLE TYPE ('TYPE CONFUSION') CWE-843
ICMP echo packets with fake IP options allow sending ICMP echo reply messages
to arbitrary hosts on the network.
CVE-2021-31344 has been assigned to this vulnerability. A CVSS v3 base score of
5.3 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/
C:N/I:L/A:N ).
3.2.2 IMPROPER VALIDATION OF SPECIFIED QUANTITY IN INPUT CWE-1284
The total length of an UDP payload (set in the IP header) is unchecked. This
may lead to various side effects including information leakage and
denial-of-service conditions.
CVE-2021-31345 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/
C:H/I:N/A:N ).
3.2.3 IMPROPER VALIDATION OF SPECIFIED QUANTITY IN INPUT CWE-1284
The total length of an ICMP payload (set in the IP header) is unchecked. This
may lead to various side effects including information leakage and
denial-of-service conditions.
CVE-2021-31346 has been assigned to this vulnerability. A CVSS v3 base score of
8.2 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:U/
C:L/I:N/A:H ).
3.2.4 BUFFER ACCESS WITH INCORRECT LENGTH VALUE CWE-805
TFTP server application allows for reading the contents of the TFTP memory
buffer by sending malformed TFTP commands.
CVE-2021-31885 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/
C:H/I:N/A:N ).
3.2.5 INTEGER UNDERFLOW (WRAP OR WRAPAROUND) CWE-191
Malformed TCP packets with a corrupted SACK option can lead to information
leaks and denial-of-service conditions.
CVE-2021-31889 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/
C:N/I:N/A:H ).
3.2.6 IMPROPER HANDLING OF INCONSISTENT STRUCTURAL ELEMENTS CWE-240
The total length of an TCP payload (set in the IP header) is unchecked. This
may lead to various side effects including information leakage and
denial-of-service conditions.
CVE-2021-31890 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/
C:N/I:N/A:H ).
3.3 BACKGROUND
o CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors
o COUNTRIES/AREAS DEPLOYED: Worldwide
o COMPANY HEADQUARTERS LOCATION: Germany
3.4 RESEARCHER
Siemens reported these vulnerabilities to CISA.
4. MITIGATIONS
Siemens Energy has indicated no remediation is planned.
Siemens Energy has identified the following specific workarounds and
mitigations users can apply to reduce the risk:
o PLUSCONTROL devices are typically located in a separate LAN segment of
energy transmission solutions, where an attacker could use these
vulnerabilities to disrupt SER messages or Trace functionalities.
Therefore, review the status of the defense-in-depth recommendations as
they apply specific deployments and align as needed. Users are encouraged
to pay special attention to the measures on the network layer to prevent
accessibility from other network segments.
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-845392
CISA recommends users take defensive measures to minimize the risk of
exploitation of these vulnerabilities. Specifically, users should:
o Minimize network exposure for all control system devices and/or systems,
and ensure 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 VPNs may have vulnerabilities and should be
updated to the most current version available. Also recognize VPN is only
as secure as its 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 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 cisa.gov in the Technical Information Paper,
ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation
Strategies .
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 these vulnerabilities.
For any questions related to this report, please contact the CISA at:
Email: CISAservicedesk@cisa.dhs.gov
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.
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=K3V6
-----END PGP SIGNATURE-----