8.6 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
HIGH
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
0.002 Low
EPSS
Percentile
54.3%
This updated advisory is a follow-up to the original advisory titled ICSA-23-138-02 Mitsubishi Electric MELSEC WS Series that was published May 18th, 2023, on the ICS webpage on cisa.gov/ICS.
Successful exploitation of this vulnerability could allow an attacker to bypass authentication and log in by connecting to the module via telnet to reset the module or, if certain conditions are met, either disclose or tamper with the moduleβs configuration, or rewrite the firmware.
--------- Begin Update A Part 1 of 2 --------
The following versions of Mitsubishi Electric MELSEC WS Series, an ethernet interface module, are affected:
--------- End Update A Part 1 of 2 ---------
4.2.1 ACTIVE DEBUG CODE CWE-489
In the affected products, the hidden telnet function is enabled by default when shipped from the factory. An authentication bypass vulnerability could allow a remote unauthenticated attacker to log into the affected module by connecting to it via telnet.
CVE-2023-1618 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:H/A:N).
Mitsubishi Electric reported this vulnerability to CISA.
--------- Begin Update A Part 2 of 2 --------
Mitsubishi Electric has released the following versions to fix this vulnerability:
For the affected products, Mitsubishi Electric recommends users to take the following mitigation measures:
Alternatively, Mitsubishi Electric recommends that users take the following mitigation measures to minimize the risk of exploiting this vulnerability:
--------- End Update A Part 2 of 2 ---------
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 exploitation specifically targeting this vulnerability has been reported to CISA at this time.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-1618
cisa.gov/ics
cisa.gov/ics
cwe.mitre.org/data/definitions/489.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Mitsubishi%20Electric%20MELSEC%20WS%20Series%20%28UPDATE%20A%29+https://www.cisa.gov/news-events/ics-advisories/icsa-23-138-02
us-cert.cisa.gov/ics/Recommended-Practices
us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
www.cisa.gov/uscert/ics/tips/ICS-TIP-12-146-01B
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-23-138-02&title=Mitsubishi%20Electric%20MELSEC%20WS%20Series%20%28UPDATE%20A%29
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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-23-138-02
www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2023-002_en.pdf
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-23-138-02
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Mitsubishi%20Electric%20MELSEC%20WS%20Series%20%28UPDATE%20A%29&body=www.cisa.gov/news-events/ics-advisories/icsa-23-138-02