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
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.9 High
AI Score
Confidence
High
0.006 Low
EPSS
Percentile
77.8%
Successful exploitation of this vulnerability could allow an attacker with network access to an affected device to cause a remote code execution condition.
The following Siemens products are affected:
3.2.1 CLASSIC BUFFER OVERFLOW CWE-120
The DHCP client in affected devices fails to properly sanitize incoming DHCP packets. This could allow an unauthenticated remote attacker to cause memory to be overwritten, potentially allowing remote code execution.
CVE-2021-31895 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
Siemens reported this vulnerability to CISA.
Siemens recommends applying updates where applicable:
Siemens has 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 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-373591.
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. This vulnerability has a high attack complexity.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31895
cert-portal.siemens.com/operational-guidelines-industrial-security.pdf
cert-portal.siemens.com/productcert/pdf/ssa-373591.pdf
cwe.mitre.org/data/definitions/120.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/gb/en/view/109797844
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
support.industry.siemens.com/cs/us/en/view/109799880
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20RUGGEDCOM%20ROS+https://www.cisa.gov/news-events/ics-advisories/icsa-21-194-10
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
www.facebook.com/sharer/sharer.php?u=https://www.cisa.gov/news-events/ics-advisories/icsa-21-194-10&title=Siemens%20RUGGEDCOM%20ROS
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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-21-194-10
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-194-10
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20RUGGEDCOM%20ROS&body=www.cisa.gov/news-events/ics-advisories/icsa-21-194-10
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
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.9 High
AI Score
Confidence
High
0.006 Low
EPSS
Percentile
77.8%