5.3 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
5.9 Medium
AI Score
Confidence
High
4.6 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
0.0004 Low
EPSS
Percentile
12.2%
Successful exploitation of this vulnerability may allow the control programmer to call additional OS functions from the PLC logic utilizing the SysFile system library.
CODESYS reports all runtime systems for Linux based on a CODESYS V2 Runtime Toolkit 32-bit full prior Version 2.4.7.55 are affected.
The CODESYS Control runtime system enables embedded or PC-based devices to operate as programmable industrial controllers. Control programs can access local or remote input/output (I/O) locations, communication interfaces such as serial ports or sockets, and local system functions such as the file system, real-time clock, and other OS functions. An attacker could exploit this vulnerability to call additional OS functions via the SysFile system library.
CVE-2021-30187 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L).
Sergey Fedonin and Ivan Kurnak, of Positive Technologies reported this vulnerability to CODESYS.
CODESYS GmbH has released CODESYS Runtime Toolkit 32-bit full Version 2.4.7.55 to solve the noted vulnerability issue for the affected CODESYS products.
Please visit the CODESYS update area for more information on how to obtain 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 2021-08 for more information.
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. 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 this vulnerability.
web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-30187
customers.codesys.com/fileadmin/data/customers/security/CODESYS-Security-Whitepaper.pdf
customers.codesys.com/index.php?eID=dumpFile&t=f&f=14727&token=25159b0fc4355f4c6bc2e074a519a9d0cdb23fbb&download=
cwe.mitre.org/data/definitions/78.html
public.govdelivery.com/accounts/USDHSCISA/subscriber/new?topic_id=USDHSCISA_138
twitter.com/CISAgov
twitter.com/intent/tweet?text=CODESYS%20Control%20V2%20Linux%20SysFile%20library+https://www.cisa.gov/news-events/ics-advisories/icsa-21-173-04
us-cert.cisa.gov/ics
us-cert.cisa.gov/ics
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.codesys.com/download
www.dhs.gov
www.dhs.gov/foia
www.dhs.gov/performance-financial-reports
www.facebook.com/CISA
www.facebook.com/sharer/sharer.php?u=https://www.cisa.gov/news-events/ics-advisories/icsa-21-173-04&title=CODESYS%20Control%20V2%20Linux%20SysFile%20library
www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
www.instagram.com/cisagov
www.linkedin.com/company/cybersecurity-and-infrastructure-security-agency
www.linkedin.com/sharing/share-offsite/?url=https://www.cisa.gov/news-events/ics-advisories/icsa-21-173-04
www.oig.dhs.gov/
www.surveymonkey.com/r/CISA-cyber-survey?product=https://www.cisa.gov/news-events/ics-advisories/icsa-21-173-04
www.usa.gov/
www.whitehouse.gov/
www.youtube.com/@cisagov
mailto:?subject=CODESYS%20Control%20V2%20Linux%20SysFile%20library&body=www.cisa.gov/news-events/ics-advisories/icsa-21-173-04
5.3 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
5.9 Medium
AI Score
Confidence
High
4.6 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
0.0004 Low
EPSS
Percentile
12.2%