7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8 High
AI Score
Confidence
High
7.2 High
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
0.0004 Low
EPSS
Percentile
9.8%
Successful exploitation of these vulnerabilities could allow an attacker to escalate unnecessary privileges and use hard-coded credentials to take control of the device.
The following firmware versions of MU320E are affected:
The software contains a hard-coded password that could allow an attacker to take control of the merging unit using these hard-coded credentials.
CVE-2021-27452 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
A miscommunication in the file system allows adversaries with access to the MU320E to escalate privileges.
CVE-2021-27448 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been assigned; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
SSH server configuration file does not implement some best practices. This could lead to a weakening of the SSH protocol strength, which could lead to additional misconfiguration or be leveraged as part of a larger attack.
CVE-2021-27450 has been assigned to this vulnerability. A CVSS v3 base score of 3.8 has been assigned; the CVSS vector string is (AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L).
Tom Westenberg of Thales UK reported these vulnerabilities to GE.
GE recommends MU320E users upgrade to firmware v04A00.1 or higher to mitigate these vulnerabilities.
Instructions on how to upgrade the MU320E firmware and verify its installation are available in the product userβs manual.
See GE publication number: GES-2021-003 for more information.
GE recommends MU320E devices be protected using network defense-in-depth practices. This includes, but is not limited to, placing MU320E devices inside the control system network security perimeter, and having access controls, monitoring (such as an Intrusion Detection System), and other mitigating technologies in place. Many electric utilities have deployed cyber security solutions in accordance with the NERC-CIP implementation requirements. Please refer to the product secure deployment guide.
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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-12-146-01BβTargeted 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-2021-27448
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-27450
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-27452
cwe.mitre.org/data/definitions/250.html
cwe.mitre.org/data/definitions/259.html
cwe.mitre.org/data/definitions/326.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
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us-cert.cisa.gov/ics
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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
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www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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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mailto:?subject=GE%20MU320E&body=www.cisa.gov/news-events/ics-advisories/icsa-21-082-02
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8 High
AI Score
Confidence
High
7.2 High
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
0.0004 Low
EPSS
Percentile
9.8%