7.5 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.6 High
AI Score
Confidence
High
0.002 Low
EPSS
Percentile
57.1%
Successful exploitation of these vulnerabilities could allow an attacker to log in as a currently or previously authenticated user or discover passwords for valid users.
Automation Direct reports these vulnerabilities affect the following CLICK PLC CPU modules:
The firmware does not protect against additional software programming connections. An attacker can connect to the PLC while an existing connection is already active.
CVE-2021-32980 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
All programming connections receive the same unlocked privileges, which can result in a privilege escalation. During the time the PLC is unlocked by an authorized user, an attacker can connect to the PLC and read the project without authorization.
CVE-2021-32984 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
After the PLC is unlocked by an authorized user, the unlocked state does not timeout. If the programming software is interrupted, the PLC remains unlocked. All subsequent programming connections are allowed without authorization. The PLC is only relocked by a power cycle, or when the programming software disconnects correctly.
CVE-2021-32986 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
Passwords are sent as plaintext during unlocking and project transfers. An attacker who has network visibility can observe the password exchange.
CVE-2021-32982 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:H/I:N/A:N).
The programming protocol allows for a previously entered password and lock state to be read by an attacker. If the previously entered password was successful, the attacker can then use the password to unlock the PLC.
CVE-2021-32978 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:H/I:N/A:N).
Irfan Ahmed and Adeen Ayub of Virginia Commonwealth University and Hyunguk Yoo of the University of New Orleans reported these vulnerabilities to Automation Direct.
Automation Direct reports these vulnerabilities are all mitigated by Version 3.00 and recommends users update software and firmware to the latest version.
Automation Direct also recommends users follow its security guidelines.
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 on us-cert.cisa.gov. 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 webpage on us-cert.cisa.gov 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 CISA for tracking and correlation against other incidents.
No known public exploits specifically target these vulnerabilities.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-32978
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-32980
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-32982
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-32984
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-32986
cdn.automationdirect.com/static/manuals/c0userm/appxa.pdf
cwe.mitre.org/data/definitions/256.html
cwe.mitre.org/data/definitions/288.html
cwe.mitre.org/data/definitions/288.html
cwe.mitre.org/data/definitions/288.html
cwe.mitre.org/data/definitions/319.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=Automation%20Direct%20CLICK%20PLC%20CPU%20Modules+https://www.cisa.gov/news-events/ics-advisories/icsa-21-166-02
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics/alerts/ICS-ALERT-10-301-01
us-cert.cisa.gov/ics/recommended-practices
us-cert.cisa.gov/ics/tips/ICS-TIP-12-146-01B
us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
www.automationdirect.com/support/software-downloads?itemcode=CLICK
www.dhs.gov
www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
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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:H/I:H/A:H
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7.5 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
9.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.6 High
AI Score
Confidence
High
0.002 Low
EPSS
Percentile
57.1%