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
0.004 Low
EPSS
Percentile
72.1%
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemensβ ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
This updated advisory is a follow-up to the original advisory titled ICSA-22-286-07 Siemens Nucleus RTOS FTP Server that was published October 13, 2022, on the ICS webpage on cisa.gov/ICS.
Successful exploitation of this vulnerability could allow a remote attacker to generate a denial-of-service condition on devices running the affected software.
The following Nucleus RTOS components contain the affected File Transport Protocol (FTP) server:
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The FTP server does not properly release memory resources reserved for incomplete connection attempts by FTP clients. This could allow a remote attacker to generate a denial-of-service condition on devices incorporating a vulnerable version of the FTP server.
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CVE-2022-38371 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
Siemens reported this vulnerability to CISA.
Siemens recommends updating to the latest version of its software where available:
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Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:
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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 associated Siemens Security Advisory in HTML or CSAF formats.
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 at cisa.gov/ics. Several CISA products detailing cyber defense best 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 at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01BβTargeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report 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-2022-38371
cert-portal.siemens.com/productcert/csaf/ssa-313313.json
cert-portal.siemens.com/productcert/html/ssa-313313.html
cisa.gov/ics
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cwe.mitre.org/data/definitions/400.html
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