CVE-2024-8935
highpriority · track · 0EPSS 0.005 · 44 %ileEURUUSEPSS · scored 2026-10-27
CWE-290: Authentication Bypass by Spoofing vulnerability exists that could cause a denial of service and loss of confidentiality and integrity of controllers when conducting a Man-In-The-Middle attack between the controller and the engineering workstation while a valid user is establishing a communication session. This vulnerability is inherent to Diffie Hellman algorithm which does not protect against Man-In-The-Middle attacks.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedEcoStruxure™ Control Expertcisa_csaf_ot
EcoStruxure™ Control Expert V16.2 HF003 includes a fix for this vulnerability and is available for download here: https://www.se.com/ww/en/product-range/548-ecostruxure-control-expert-unity-pro/#software-and-firmware
https://www.se.com/ww/en/product-range/548-ecostruxure-control-expert-unity-pro/#software-and-firmware - FixedModicon M340 CPU Firmware Versions since SV3.60 and prior to SV3.70 installed on Modicon M340 CPU Controller (part numbers BMXP34*)cisa_csaf_ot
Version 3.70 of Modicon M340 includes a fix for this vulnerability and is available for download here: https://www.se.com/ww/en/product-range/1468-modicon-m340/#software-and-firmware
https://www.se.com/ww/en/product-range/1468-modicon-m340/#software-and-firmware - MitigationEcoStruxure™ Control Expertcisa_csaf_ot
Customers should immediately apply the following mitigations to reduce the risk of exploit: • Setup network segmentation and implement a firewall to block all unauthorized access to port 502/TCP • Configure the Access Control List following the recommendations of the user manuals: “Momentum for EcoStruxure™ Control Expert - 171CBU78090, 171CBU98090, 171CBU98091 Processors, User Guide” in the section “Controlling Access”: https://www.se.com/ww/en/download/document/HRB44124/ • Consider use of external firewall devices such as EAGLE40-07 from Belden to establish VPN connections. For more details refer to “Modicon Controller Systems Cybersecurity, User Guide”: https://www.se.com/ww/en/download/document/EIO0000001999/
https://www.se.com/ww/en/download/document/HRB44124/ - MitigationModicon M340 CPU Firmware Versions since SV3.60 and prior to SV3.70 installed on Modicon M340 CPU Controller (part numbers BMXP34*)cisa_csaf_ot
Customers should immediately apply the following mitigations to reduce the risk of exploit: • Setup network segmentation and implement a firewall to block all unauthorized access to port 502/TCP • Configure the Access Control List following the recommendations of the user manuals: “Modicon M340 for Ethernet Communications Modules and Processors User Manual” in chapter “Messaging Configuration Parameters”: https://www.se.com/ww/en/download/document/31007131K01000/ • Consider use of external firewall devices such as EAGLE40-07 from Belden to establish VPN connections. For more details refer to “Modicon Controller Systems Cybersecurity, User Guide”: https://www.se.com/ww/en/download/document/EIO0000001999/ • Ensure the M340 CPU is running with the memory protection activated by configuring the input bit to a physical input, for more details refer to the following guideline “Modicon Controller Systems Cybersecurity, User Guide” chapter “Controler Memory Protection”: https://www.se.com/ww/en/download/document/EIO0000001999/
https://www.se.com/ww/en/download/document/31007131K01000/
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.2–7.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (13)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- ICSA-24-326-03Schneider Electric Modicon M340, MC80, and Momentum Unity M1E & EcoStruxure (Update A)2024-11-12icsa · cisa_csaf_otUS
Schneider Electric is aware of multiple vulnerabilities in its Modicon Controllers M340 / Momentum / MC80 / EcoStruxure™ Control Expert products. [Modicon PAC](https://www.se.com/ww/en/product-subcategory/3950-pac-programmable-automation-controllers/?filter=business-1-industrial-automation-and-control) products control and monitor industrial operations. [EcoStruxure™ Control Expert](https://www.se.com/ww/en/product-range/548-ecostruxure-control-expert-unity-pro/#overview) is the engineering application for Modicon Controllers. Failure to apply the provided remediations/mitigations below may risk unauthorized access to the controller, which could result in the possibility of denial of service and loss of confidentiality, integrity of the controller.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://download.schneider-electric.com/doc/SEVD-2024-317-02/SEVD-2024-317-02.pdfcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2024-8935cnnvd
- https://download.schneider-electric.com/doc/SEVD-2024-317-02/SEVD-2024-317-02.pdfenisa_euvd
- https://download.schneider-electric.com/doc/SEVD-2024-317-02/SEVD-2024-317-02.pdfnvd
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