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
High
EPSS
Percentile
64.7%
Successful exploitation of these vulnerabilities may cause a heap-based buffer overflow, a stack-based buffer overflow, or a buffer over-read in the affected CODESYS products. This could result in a denial-of-service condition or allow remote code execution.
CODESYS reports the following CODESYS V2 runtime systems are affected, regardless of the CPU type or operating system:
A crafted request may cause a heap-based buffer overflow in the affected CODESYS products, resulting in a denial-of-service condition.
CVE-2021-30186 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:N/I:N/A:H).
A crafted request may cause a stack-based buffer overflow in the affected CODESYS products, resulting in a denial-of-service condition or remote code execution.
CVE-2021-30188 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).
A crafted request may cause a buffer over-read in the affected CODESYS products, resulting in a denial-of-service condition.
CVE-2021-30195 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:N/I:N/A:H).
Sergey Fedonin, Denis Goryushev, and Anton Dorfman of Positive Technologies; and Yossi Reuven of SCADAfence independently reported these vulnerabilities to CODESYS.
CODESYS GmbH has released the following product versions to solve the noted vulnerability issues for the affected CODESYS products:
Please visit the CODESYS update area for more information on how to obtain the software updates.
As part of a security strategy, CODESYS recommends the following general defense measures to reduce the risk of exploits:
For more information and general recommendations for protecting machines and plants, see also the CODESYS Security Whitepaper.
Please see CODESYS Advisory 2021-06 for more information.
CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. 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-2021-30186
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-30188
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-30195
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customers.codesys.com/fileadmin/data/customers/security/CODESYS-Security-Whitepaper.pdf
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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
High
EPSS
Percentile
64.7%