3.3 Low
CVSS2
Attack Vector
ADJACENT_NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:A/AC:L/Au:N/C:P/I:N/A:N
6.5 Medium
CVSS3
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
6.6 Medium
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
26.0%
This updated advisory is a follow-up to the original advisory titled ICSA-21-132-10 Siemens SIMATIC CP that was published September 14, 2021, to the ICS webpage at cisa.gov/ics.
Successful exploitation of this vulnerability could allow an attacker to read sensitive information.
The following versions of SIMATIC, a communication processor, are affected:
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--------- End Update A Part 1 of 2 ---------
An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.
CVE-2021-33716 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been assigned; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
Siemens reported this vulnerability to CISA.
--------- Begin Update A Part 2 of 2 ---------
Siemens recommends applying updates where applicable:
--------- End Update A Part 2 of 2 ---------
For SIMATIC CP 1543-1 (incl. SIPLUS variants), Siemens recommends affected users update to v3.0 or later and migrate the TIA Portal engineering project to v17. After migrating the project successfully, compilation and download to the device is required. See this productβs Siemens Product Support entry for more information.
For SIMATIC CP 1545-1, Siemens has not identified any additional specific workarounds or mitigations.
As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemensβ operational guidelines for industrial security and following recommendations in the product manuals.
Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage.
For more information about this issue, please see Siemens Security Advisory SSA-535997
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 cisa.gov/ics 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/ics in the Technical Information Paper, ICS-TIP-12-146-01BβTargeted 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.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-33716
cert-portal.siemens.com/productcert/pdf/ssa-535997.pdf
cisa.gov/ics
cisa.gov/ics
cwe.mitre.org/data/definitions/312.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/ww/en/view/109800773/
support.industry.siemens.com/cs/ww/en/view/109811116
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20SIMATIC%20CP%20%28Update%20A%29+https://www.cisa.gov/news-events/ics-advisories/icsa-21-257-06
www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01
www.cisa.gov/uscert/ics/recommended-practices
www.cisa.gov/uscert/ics/tips/ICS-TIP-12-146-01B
www.cisa.gov/uscert/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:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
www.instagram.com/cisagov
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www.linkedin.com/sharing/share-offsite/?url=https://www.cisa.gov/news-events/ics-advisories/icsa-21-257-06
www.oig.dhs.gov/
www.siemens.com/cert/operational-guidelines-industrial-security
www.siemens.com/industrialsecurity
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-257-06
www.usa.gov/
www.whitehouse.gov/
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mailto:?subject=Siemens%20SIMATIC%20CP%20%28Update%20A%29&body=www.cisa.gov/news-events/ics-advisories/icsa-21-257-06
3.3 Low
CVSS2
Attack Vector
ADJACENT_NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:A/AC:L/Au:N/C:P/I:N/A:N
6.5 Medium
CVSS3
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
6.6 Medium
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
26.0%