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
9.4 High
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
66.3%
CVSS v3 7.7
ATTENTION: Exploitable remotely
**Vendor:**Schneider Electric
**Equipment:**Modicon M221
**Vulnerabilities:**Information Management Errors, Permissions, Privileges, and Access Controls
Successful exploitation of these vulnerabilities may allow unauthorized users to replay authentication sequences, overwrite passwords, or decode passwords.
Schneider Electric reports the vulnerabilities affect the following Modicon M221 products:
3.2.1 INFORMATION MANAGEMENT ERRORS CWE-199
This vulnerability allows unauthorized users to replay authentication sequences.
If an attacker exploits this vulnerability and connects to a Modicon M221, the attacker may upload the original program from the PLC.
CVE-2018-7790 has been assigned to this vulnerability. A CVSS v3 base score of 7.1 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L).
3.2.2 PERMISSIONS, PRIVILEGES, AND ACCESS CONTROLS CWE-264
This vulnerability allows unauthorized users to overwrite the original password.
If an attacker exploits this vulnerability and overwrites the password, the attacker may upload the original program from the PLC.
CVE-2018-7791 has been assigned to this vulnerability. A CVSS v3 base score of 7.7 has been assigned; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L).
3.2.3 PERMISSIONS, PRIVILEGES, AND ACCESS CONTROLS CWE-264
This vulnerability allows unauthorized users to decode the password using a rainbow table.
CVE-2018-7792 has been assigned to this vulnerability. A CVSS v3 base score of 7.7 has been assigned; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L).
Irfan Ahmed, Hyunguk Yoo, Sushma Kalle, and Nehal Ameen of the University of New Orleans reported these vulnerabilities to NCCIC.
A fix for these vulnerabilities is implemented in Modicon M221 Firmware v1.6.2.0, delivered within SoMachine Basic v1.6 SP2, which is available for download below, or by using Schneider Electric Software Update tool:
<https://www.schneider-electric.com/en/download/document/SoMachineBasicV1.6SP2/>
As a temporary mitigation, Modicon M221 users should take the following measures:
Schneider Electricโs security notice SEVD-2018-235-01 is available at the following location:
<https://www.schneider-electric.com/en/download/document/SEVD-2018-235-01/>
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-12-146-01BโTargeted 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 these vulnerabilities. High skill level is needed to exploit.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7790
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7791
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-7792
cwe.mitre.org/data/definitions/199.html
cwe.mitre.org/data/definitions/264.html
cwe.mitre.org/data/definitions/264.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
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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
9.4 High
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
66.3%