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
7.8 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:N/I:N/A:C
0.783 High
EPSS
Percentile
98.2%
This updated advisory is a follow-up to the advisory update titled ICSA-20-105-05 Siemens IE/PB-Link, RUGGEDCOM, SCALANCE, SIMATIC, SINEMA (Update A) that was published May 12, 2020, on the ICS webpage on us-cert.gov.
Successful exploitation of these vulnerabilities could allow remote attackers to affect the availability of the devices under certain conditions.
The following Siemens products are affected:
--------- Begin Update B Part 1 of 2 ---------
--------- End Update B Part 1 of 2 ---------
Certain Linux kernel versions can be forced to make resource intensive calls for every incoming packet, which can lead to a denial-of-service condition.
CVE-2018-5390 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).
Certain Linux kernels are vulnerable to a denial-of-service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial-of-service condition by sending specially crafted IP fragments.
CVE-2018-5391 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 to CISA that these publicly known vulnerabilities also affect these products.
Siemens recommends applying updates, where available:
--------- Begin Update B Part 2 of 2 ---------
--------- End Update B Part 2 of 2 ---------
Siemens has not identified any specific mitigations or workarounds and recommends following their general security recommendations. 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 the Siemens operational guidelines for Industrial Security and following the recommendations in the product manuals.
For additional information, please refer to Siemens Security Advisory SSA-377115
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.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.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.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-5390
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-5391
cert-portal.siemens.com/productcert/pdf/ssa-377115.pdf
cwe.mitre.org/data/definitions/20.html
cwe.mitre.org/data/definitions/400.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/ww/en/view/109769665
support.industry.siemens.com/cs/ww/en/view/109773308
support.industry.siemens.com/cs/ww/en/view/109773734
support.industry.siemens.com/cs/ww/en/view/109774207
support.industry.siemens.com/cs/ww/en/view/109774207
support.industry.siemens.com/cs/ww/en/view/109774207
support.industry.siemens.com/cs/ww/en/view/109774207
support.industry.siemens.com/cs/ww/en/view/109775640
support.industry.siemens.com/cs/ww/en/view/109775640
support.industry.siemens.com/cs/ww/en/view/109775640
support.industry.siemens.com/cs/ww/en/view/109775642/
support.industry.siemens.com/cs/ww/en/view/109778305
support.industry.siemens.com/cs/ww/en/view/109778305
support.industry.siemens.com/cs/ww/en/view/109778537
support.industry.siemens.com/cs/ww/en/view/109778537
support.industry.siemens.com/cs/ww/en/view/109781665
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20RUGGEDCOM%2C%20SCALANCE%2C%20SIMATIC%2C%20SINEMA%20%28Update%20B%29+https://www.cisa.gov/news-events/ics-advisories/icsa-20-105-05
www.dhs.gov
www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
www.facebook.com/CISA
www.facebook.com/sharer/sharer.php?u=https://www.cisa.gov/news-events/ics-advisories/icsa-20-105-05&title=Siemens%20RUGGEDCOM%2C%20SCALANCE%2C%20SIMATIC%2C%20SINEMA%20%28Update%20B%29
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.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-20-105-05
www.oig.dhs.gov/
www.siemens.com/cert/operational-guidelines-industrial-security
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-20-105-05
www.us-cert.gov/ics
www.us-cert.gov/ics
www.us-cert.gov/ics/recommended-practices
www.us-cert.gov/ics/tips/ICS-TIP-12-146-01B
www.us-cert.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20RUGGEDCOM%2C%20SCALANCE%2C%20SIMATIC%2C%20SINEMA%20%28Update%20B%29&body=www.cisa.gov/news-events/ics-advisories/icsa-20-105-05
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
7.8 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:N/I:N/A:C
0.783 High
EPSS
Percentile
98.2%