7.8 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:N/I:N/A:C
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
8.3 High
AI Score
Confidence
High
0.002 Low
EPSS
Percentile
61.3%
Successful exploitation of these vulnerabilities could allow a remote attacker to cause a denial-of-service condition. Recovery requires a system reset.
The following versions of MELSEC series CPU modules and MELIPC Series Industrial Computers are affected:
3.2.1 UNCONTROLLED RESOURCE CONSUMPTION CWE-400
The product does not properly control the allocation and maintenance of a limited resource, and could thereby enable an actor to influence resource consumption, eventually leading to the exhaustion of available resources.
CVE-2021-20609 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).
3.2.2 IMPROPER HANDLING OF LENGTH PARAMETER INCONSISTENCY CWE-130
The product parses a formatted message or structure, but does not handle or incorrectly handles a length field inconsistent with the actual length of the associated data.
CVE-2021-20610 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).
3.2.3 IMPROPER INPUT VALIDATION CWE-20
The product receives input or data, but does not validate or incorrectly validates that the input has the properties required to process the data safely and correctly.
CVE-2021-20611 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).
Mitsubishi Electric reported these vulnerabilities to CISA.
Mitsubishi Electric corrected the vulnerabilities in the following products and intends to do the same with other products.
Mitsubishi Electric recommends users take the following mitigation measures to minimize the risk of an attacker exploiting these vulnerabilities:
For specific update instructions and additional details, see the [Mitsubishi Electric advisory].(<https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-019_en.pdf>).
CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. 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 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-12-146-01B–Targeted 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 these vulnerabilities has been reported to CISA at this time.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-20609
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-20610
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-20611
cisa.gov/ics
cisa.gov/ics
cwe.mitre.org/data/definitions/130.html
cwe.mitre.org/data/definitions/20.html
cwe.mitre.org/data/definitions/400.html
github.com/cisagov/CSAF
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Mitsubishi%20Electric%20MELSEC%20and%20MELIPC%20Series%20%28Update%20G%29+https://www.cisa.gov/news-events/ics-advisories/icsa-21-334-02
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/alerts/ICS-ALERT-10-301-01
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-21-334-02&title=Mitsubishi%20Electric%20MELSEC%20and%20MELIPC%20Series%20%28Update%20G%29
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.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-21-334-02
www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-019_en.pdf
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-334-02
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Mitsubishi%20Electric%20MELSEC%20and%20MELIPC%20Series%20%28Update%20G%29&body=www.cisa.gov/news-events/ics-advisories/icsa-21-334-02
7.8 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:N/I:N/A:C
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
8.3 High
AI Score
Confidence
High
0.002 Low
EPSS
Percentile
61.3%