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
7.7 High
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
70.0%
CVSS v3 4.8
ATTENTION: Exploitable remotely
Vendor: Schneider Electric
Equipment: Modicon M221
Vulnerability: Improper Check for Unusual or Exceptional Conditions
Successful exploitation of this vulnerability could allow an unauthorized user to remotely reboot the device.
The following versions of Modicon M221, a programmable logic controller (PLC), are affected:
The vulnerability may allow unauthorized users to remotely reboot Modicon M221 using crafted programing protocol frames.
CVE-2018-7789 has been assigned to this vulnerability. A CVSS v3 base score of 4.8 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L).
Schneider Electric, working with Yehonatan Kfir of Radiflow, reported the vulnerability to NCCIC.
Schneider Electric reports that a fix for this vulnerability is implemented in Modicon M221 Firmware v1.6.2.0, delivered within SoMachine Basic v1.6 SP2, or by using the Schneider Electric Software Update tool.
The download for SoMachine Basic is available at:
<https://www.schneider-electric.com/en/download/document/SoMachineBasicV1.6SP2/>
For more information, see the Schneider Electric security notification at:
<https://www.schneider-electric.com/en/download/document/SEVD-2018-233-01/>
NCCIC recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:
NCCIC reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
NCCIC also provides a section for control systems security recommended practices on the ICS-CERT web page. 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-CERT website in the Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to NCCIC for tracking and correlation against other incidents.
No known public exploits specifically target this vulnerability. High skill level is needed to exploit.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7789
cwe.mitre.org/data/definitions/754.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Schneider%20Electric%20Modicon%20M221+https://www.cisa.gov/news-events/ics-advisories/icsa-18-240-02
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:H/PR:N/UI:N/S:U/C:N/I:L/A:L
www.instagram.com/cisagov
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www.linkedin.com/sharing/share-offsite/?url=https://www.cisa.gov/news-events/ics-advisories/icsa-18-240-02
www.oig.dhs.gov/
www.schneider-electric.com/en/download/document/SEVD-2018-233-01/
www.schneider-electric.com/en/download/document/SoMachineBasicV1.6SP2/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-18-240-02
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=Schneider%20Electric%20Modicon%20M221&body=www.cisa.gov/news-events/ics-advisories/icsa-18-240-02
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
7.7 High
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
70.0%