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
8.8 High
AI Score
Confidence
Low
0.003 Low
EPSS
Percentile
72.0%
This updated advisory is a follow-up to the original advisory titled βICSA-21-350-06 Siemens Capital VSTARβ that was published December 16, 2021, on the ICS webpage on cisa.gov/ICS.
Successful exploitation of these vulnerabilities could be leveraged by an attacker to initiate a crash, information leak, denial-of-service conditions, or remote code execution.
The following versions of Capital VSTAR software platform are affected because of their use of Nucleus NET, the networking stack of Nucleus RTOS (real-time operating system):
ICMP echo packets with fake IP options allow sending ICMP echo reply messages to arbitrary hosts on the network.
CVE-2021-31344 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N).
The total length of an UDP payload (set in the IP header) is unchecked. This may lead to various side effects, including information leak and denial-of-service conditions, depending on a user-defined applications that runs on top of the UDP protocol.
CVE-2021-31345 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:H/I:N/A:N).
The total length of an ICMP payload (set in the IP header) is unchecked. This may lead to various side effects, including information leak and denial-of-service conditions, depending on the network buffer organization in memory.
CVE-2021-31346 has been assigned to this vulnerability. A CVSS v3 base score of 8.2 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H).
When processing a DHCP OFFER message, the DHCP client application does not validate the length of the vendor option(s), leading to denial-of-service conditions.
CVE-2021-31881 has been assigned to this vulnerability. A CVSS v3 base score of 7.1 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H).
The DHCP client application does not validate the length of the domain name server IP option(s) (0x06) when processing DHCP ACK packets. This may lead to denial-of-service conditions.
CVE-2021-31882 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
When processing a DHCP ACK message, the DHCP client application does not validate the length of the vendor option(s), leading to denial-of-service conditions.
CVE-2021-31883 has been assigned to this vulnerability. A CVSS v3 base score of 7.1 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H).
The DHCP client application assumes that the data supplied with the βHostnameβ DHCP option is NULL terminated. In cases when global hostname variable is not defined, this may lead to out-of-bound reads, writes, and denial-of-service conditions.
CVE-2021-31884 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
--------- Begin Update A part 1 of 1 ---------
Siemens has determined that Capital VSTAR is not affected by CVE-2021-31884.
--------- End Update A part 1 of 1 ---------
Malformed TCP packets with a corrupted SACK option leads to information leaks and denial-of-service conditions.
CVE-2021-31889 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:N).
The total length of an TCP payload (set in the IP header) is unchecked. This may lead to various side effects, including information leak and denial-of-service conditions, depending on the network buffer organization in memory.
CVE-2021-31890 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 these vulnerabilities to CISA.
Siemens has identified the following specific workarounds and mitigations that customers 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 Siemensβ operational guidelines for industrial security, and follow the recommendations in the product manuals.
For more information about this issue, please see Siemens security advisory SSA-620288
For further inquiries on security vulnerabilities in Siemens products and solutions, please contact Siemens ProductCERT.
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. 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. These vulnerabilities are exploitable remotely.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31344
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31345
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31346
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31881
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31882
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31883
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31884
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31884
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31889
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-31890
cert-portal.siemens.com/operational-guidelines-industrial-security.pdf
cert-portal.siemens.com/productcert/pdf/ssa-620288.pdf
cwe.mitre.org/data/definitions/119.html
cwe.mitre.org/data/definitions/119.html
cwe.mitre.org/data/definitions/1248.html
cwe.mitre.org/data/definitions/1248.html
cwe.mitre.org/data/definitions/125.html
cwe.mitre.org/data/definitions/170.html
cwe.mitre.org/data/definitions/191.html
cwe.mitre.org/data/definitions/240.html
cwe.mitre.org/data/definitions/843.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Siemens%20Capital%20VSTAR%20%28Update%20A%29+https://www.cisa.gov/news-events/ics-advisories/icsa-21-350-06
www.cisa.gov/uscert/ics
www.cisa.gov/uscert/ics
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
www.facebook.com/sharer/sharer.php?u=https://www.cisa.gov/news-events/ics-advisories/icsa-21-350-06&title=Siemens%20Capital%20VSTAR%20%28Update%20A%29
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/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:H/I:N/A:N
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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:L/A:N
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-21-350-06
www.oig.dhs.gov/
www.siemens.com/cert/advisories
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-350-06
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Siemens%20Capital%20VSTAR%20%28Update%20A%29&body=www.cisa.gov/news-events/ics-advisories/icsa-21-350-06
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
8.8 High
AI Score
Confidence
Low
0.003 Low
EPSS
Percentile
72.0%