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
0.016 Low
EPSS
Percentile
87.7%
This updated advisory is a follow-up to the advisory update titled ICSA-20-324-05 Mitsubishi Electric MELSEC iQ-R Series (Update B) that was published September 14, 2021 to the ICS webpage at www.cisa.gov/uscert.
Successful exploitation of this vulnerability could cause a denial-of-service condition for the affected product.
Mitsubishi Electric reports the vulnerability affects the following MELSEC iQ-R series CPU module products:
--------- Begin Update C Part 1 of 1 ---------
--------- End Update C Part 1 of 1 ---------
A vulnerability in MELSEC iQ-R series modules causes uncontrolled resource consumption. When a module receives a specially crafted SLMP packet from a malicious attacker, the program execution and communication could enter a denial-of-service condition.
CVE-2020-5668 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).
Xiaofei.Zhang reported this vulnerability to Mitsubishi Electric.
Mitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue:
For more information about this vulnerability and the associated mitigations, please see the vulnerability information on the Mitsubishi website.
Mitsubishi Electric also recommends the following practices to minimize the risk of exploiting this vulnerability:
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.
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 this vulnerability.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-5668
cwe.mitre.org/data/definitions/400.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
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www.cisa.gov/uscert/ics
www.cisa.gov/uscert/ics/recommended-practices
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
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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
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www.mitsubishielectric.com/en/psirt/vulnerability/index.html
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-20-324-05
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
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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
0.016 Low
EPSS
Percentile
87.7%