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
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
AI Score
Confidence
Low
EPSS
Percentile
59.1%
CVSS v3 10.0
ATTENTION: Exploitable remotely/low skill level to exploit
Vendor: Kunbus
Equipment: PR100088 Modbus gateway
Vulnerabilities: Improper Authentication, Information Exposure Through Query Strings in GET Request, Missing Authentication for Critical Function, Improper Input Validation, Cleartext Storage of Sensitive Information
This updated advisory is a follow-up to the advisory update titled ICSA-19-036-05 (Update A) Kunbus PR100088 Modbus Gateway that was published February 7, 2019, on the NCCIC/ICS-CERT website.
Successful exploitation of these vulnerabilities could allow an attacker to achieve remote code execution and/or cause a denial-of-service condition.
The following versions of PR100088 Modbus gateway are affected:
An attacker may be able change the password for an admin user who is currently or previously logged in, provided the device has not been restarted.
CVE-2019-6527 has been assigned to this vulnerability. A CVSS v3 base score of 9.6 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H).
Registers used to store Modbus values can be read and written from the web interface without authentication.
CVE-2019-6533 has been assigned to this vulnerability. A CVSS v3 base score of 10.0 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
An attacker could specially craft an FTP request that could crash the device.
CVE-2019-6529 has been assigned to this vulnerability. A CVSS v3 base score of 4.9 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
4.2.4 INFORMATION EXPOSURE THROUGH QUERY STRINGS IN GET REQUEST CWE-598
An attacker could retrieve passwords from an HTTP GET request if the attacker is in an MITM position.
CVE-2019-6531 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H).
4.2.5 CLEARTEXT STORAGE OF SENSITIVE INFORMATION CWE-312
An attacker could retrieve plain-text credentials stored in an XML file through FTP.
CVE-2019-6549 has been assigned to this vulnerability. A CVSS v3 base score of 7.2 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).
Nicolas Merle of Applied Risk reported these vulnerabilities to NCCIC. NCCIC coordinated these vulnerabilities with BSI Germany.
Kunbus recommends the following:
--------- Begin Update B Part 1 of 1 ---------
--------- End Update B Part 1 of 1 ---------
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 these vulnerabilities.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-6529
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-6531
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-6533
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-6549
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cwe.mitre.org/data/definitions/20.html
cwe.mitre.org/data/definitions/287.html
cwe.mitre.org/data/definitions/306.html
cwe.mitre.org/data/definitions/312.html
cwe.mitre.org/data/definitions/598.html
nvd.nist.gov/vuln/detail/CVE-2019-6527
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
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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
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
AI Score
Confidence
Low
EPSS
Percentile
59.1%