7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.6 High
AI Score
Confidence
High
5 Medium
CVSS2
Access Vector
Access Complexity
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.001 Low
EPSS
Percentile
46.3%
This updated advisory is a follow-up to the advisory update titled ICSA-21-194-03 Siemens PROFINET Devices (Update C) that was published October 14, 2021, to the ICS webpage on www.cisa.gov/uscert.
Successful exploitation of this vulnerability could allow an attacker to perform a denial-of-service attack if a large amount of PROFINET Discovery and Configuration Protocol (DCP) reset packets is sent to the affected devices.
The following Siemens products are affected:
--------- Begin Update D Part 1 of 2 ---------
--------- End Update D Part 1 of 2 ---------
Affected devices contain a vulnerability that allows an unauthenticated attacker to trigger a denial-of-service condition. This vulnerability can be triggered if a large amount of DCP resent packets are sent to the device.
CVE-2020-28400 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).
Siemens reported this vulnerability to CISA.
Siemens has provided remediations for the following affected products:
--------- Begin Update D Part 2 of 2 ---------
--------- End Update D Part 2 of 2 -------
Siemens has also identified the following specific workarounds and mitigations users can apply to reduce the risk:
As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens’ operational guidelines for Industrial Security, and to follow the recommendations in the product manuals.
Additional information on Industrial security by Siemens can be found at: <https://www.siemens.com/industrialsecurity>
For more information about this vulnerability and the associated remediations, please see Siemens publication number SSA-599968
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
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 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 this vulnerability.
support.automation.siemens.com/WW/view/en/109749989
support.automation.siemens.com/WW/view/en/109749989
support.automation.siemens.com/WW/view/en/109756912
support.automation.siemens.com/WW/view/en/109782065
support.automation.siemens.com/WW/view/en/109782067
support.automation.siemens.com/WW/view/en/109793280
support.automation.siemens.com/WW/view/en/109793952
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support.automation.siemens.com/WW/view/en/109793952
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support.automation.siemens.com/WW/view/en/109793952
support.automation.siemens.com/WW/view/en/109793952
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support.automation.siemens.com/WW/view/en/109793952
support.automation.siemens.com/WW/view/en/109794349
support.automation.siemens.com/WW/view/en/109794349
support.automation.siemens.com/WW/view/en/109794349
support.automation.siemens.com/WW/view/en/109795469
support.automation.siemens.com/WW/view/en/109799569/
support.automation.siemens.com/WW/view/en/109799569/
support.automation.siemens.com/WW/view/en/109799569/
support.automation.siemens.com/WW/view/en/109799569/
support.automation.siemens.com/WW/view/en/109799569/
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-28400
cert-portal.siemens.com/productcert/pdf/ssa-599968.pdf
cwe.mitre.org/data/definitions/770.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/ww/en/109808359
support.industry.siemens.com/cs/ww/en/109808359
support.industry.siemens.com/cs/ww/en/109808629
support.industry.siemens.com/cs/ww/en/view/109784253/
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
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support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801131
support.industry.siemens.com/cs/ww/en/view/109801629
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20PROFINET%20Devices%20%28Update%20D%29+https://www.cisa.gov/news-events/ics-advisories/icsa-21-194-03
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics/alerts/ICS-ALERT-10-301-01
us-cert.cisa.gov/ics/recommended-practices
us-cert.cisa.gov/ics/tips/ICS-TIP-12-146-01B
us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
www.dhs.gov
www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
www.facebook.com/CISA
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www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
www.instagram.com/cisagov
www.linkedin.com/company/cybersecurity-and-infrastructure-security-agency
www.linkedin.com/sharing/share-offsite/?url=https://www.cisa.gov/news-events/ics-advisories/icsa-21-194-03
www.oig.dhs.gov/
www.siemens.com/industrialsecurity
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-194-03
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20PROFINET%20Devices%20%28Update%20D%29&body=www.cisa.gov/news-events/ics-advisories/icsa-21-194-03
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.6 High
AI Score
Confidence
High
5 Medium
CVSS2
Access Vector
Access Complexity
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.001 Low
EPSS
Percentile
46.3%