7.5 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
8.6 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
HIGH
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
8.8 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
44.7%
This updated advisory is a follow-up to the original advisory titled ICSA-20-014-03 Siemens SCALANCE X Switches (Update A) that was published February 10, 2021, to the ICS webpage on www.cisa.gov/uscert.
Successful exploitation of this vulnerability could allow an unauthenticated attacker to violate access-control rules.
The following versions of SCALANCE X Switches, used to connect industrial components, are affected:
--------- Begin Update B Part 1 of 2 ---------
--------- End Update B Part 1 of 2 ---------
This vulnerability could be exploited by an attacker with network access to the affected systems. An attacker could obtain sensitive information or change the device configuration.
CVE-2019-13933 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L).
Maxim Rupp reported this vulnerability to Siemens.
Siemens recommends the following workarounds and mitigations affected users can apply to reduce risk:
--------- Begin Update B Part 2 of 2 ---------
--------- End Update B Part 2 of 2 ---------
Siemens has identified the following specific workarounds and mitigations that customers can apply to reduce the risk:
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 see the Siemens Security Advisory SSA-443566
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-2019-13933
cert-portal.siemens.com/productcert/pdf/ssa-443566.pdf
cisa.gov/ics
cisa.gov/ics
cwe.mitre.org/data/definitions/306.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/document/109773547
support.industry.siemens.com/cs/ww/en/view/109814809/
support.industry.siemens.com/cs/ww/en/view/109814809/
support.industry.siemens.com/cs/ww/en/view/109814809/
support.industry.siemens.com/cs/ww/en/view/109814809/
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20SCALANCE%20X%20Switches%20%28Update%20B%29+https://www.cisa.gov/news-events/ics-advisories/icsa-20-014-03
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:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L
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-20-014-03
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-20-014-03
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20SCALANCE%20X%20Switches%20%28Update%20B%29&body=www.cisa.gov/news-events/ics-advisories/icsa-20-014-03
7.5 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
8.6 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
HIGH
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
8.8 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
44.7%