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
6.5 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.9 High
AI Score
Confidence
High
0.082 Low
EPSS
Percentile
94.4%
This updated advisory is a follow-up to the advisory update titled ICSA-20-042-02 Siemens Industrial Products SNMP Vulnerabilities (Update E) that was published February 10, 2022, to the ICS webpage on www.cisa.gov/uscert.
Successful exploitation of these vulnerabilities could allow remote attackers to conduct a denial-of-service attack by sending specially crafted packets to Port 161/UDP (SNMP).
The following Siemens products are affected:
An error in the message handling of SNMP messages allows remote attackers to cause a denial-of-service condition and execute arbitrary code via a crafted packet sent on Port 161/UDP (SNMP).
CVE-2015-5621 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).
A NULL pointer exception bug within the SNMP handling code allows authenticated attacker to remotely cause a denial-of-service condition via a crafted packet sent on Port 161/UDP (SNMP).
CVE-2018-18065 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
Artem Zinenko of Kaspersky Lab reported these vulnerabilities to Siemens.
Siemens has released updates for several affected products and recommends users update to the new version. Siemens is preparing further updates and recommends specific countermeasures until patches are available.
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--------- End Update F Part 1 of 1 ---------
Siemens has identified the following specific workarounds and mitigations users can apply to reduce the risk:
As a general security measure, Siemens strongly recommends users protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends users configure the environment according to Siemensβ operational guidelines for Industrial Security, and 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 on the vulnerabilities and detailed mitigation instructions, please see Siemens security advisory SSA-978220
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. 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 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 these vulnerabilities.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-5621
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-18065
www.siemens.com/cert/advisories
cert-portal.siemens.com/operational-guidelines-industrial-security.pdf
cwe.mitre.org/data/definitions/19.html
cwe.mitre.org/data/definitions/476.html
new.siemens.com/global/en/products/services/cert.html#SecurityPublications
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
support.industry.siemens.com/cs/document/109756957
support.industry.siemens.com/cs/us/en/view/109792924/
support.industry.siemens.com/cs/ww/en/view/109774204
support.industry.siemens.com/cs/ww/en/view/109775589/
support.industry.siemens.com/cs/ww/en/view/109775589/
support.industry.siemens.com/cs/ww/en/view/109780330/
twitter.com/CISAgov
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www.cisa.gov/uscert/ics
www.cisa.gov/uscert/ics
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
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www.dhs.gov/foia
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www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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mailto:?subject=Siemens%20Industrial%20Products%20SNMP%20%28Update%20F%29&body=www.cisa.gov/news-events/ics-advisories/icsa-20-042-02
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
6.5 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.9 High
AI Score
Confidence
High
0.082 Low
EPSS
Percentile
94.4%