Schneider Electric Modicon Improper Input Validation (CVE-2024-11737)

critical Tenable OT Security Plugin ID 502809

Synopsis

The remote OT asset is affected by a vulnerability.

Description

An improper input validation vulnerability exists that could lead to a denial-of-service and a loss of confidentiality and integrity in the controller when an unauthenticated crafted Modbus packet is sent to the device.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

Modicon M241/M251 firmware Version 5.2.11.29 includes a fix for this vulnerability and can be updated through the Schneider Electric SoftwareUpdate (SESU) application that is part of EcoStruxure Machine Expert

Update Modicon Controller M241/M251 to the latest firmware by using Controller Assistant and perform reboot. Users should employ appropriate patching methodologies when applying these patches to their systems. Schneider Electric strongly recommends the use of back-ups and evaluating the impact of these patches in a test and development environment or on an offline infrastructure. Contact Schneider Electric's Customer Care Center for assistance removing a patch.

Schneider Electric is establishing a remediation plan for all future versions of Modicon M258/LMC058 that will include a fix for this vulnerability. They will update SEVD-2024-345-03 when the remediation is available. Until then, users should immediately apply the following mitigations to reduce the risk of exploit:

- Use controllers and devices only in a protected environment to minimize network exposure and ensure that they are not accessible from public Internet or untrusted networks.
- Filter ports and IP through the embedded firewall.
- Setup network segmentation and implement a firewall to block all unauthorized access to Port 502/TCP.
- Disable all unused protocols (default configuration).
- For more details refer to 'Cybersecurity Guidelines for EcoStruxure Machine Expert, Modicon and PacDrive Controllers and Associated Equipment Guide'
- To ensure users are informed of all updates, including details on affected products and remediation plans, Schneider Electric recommends subscription to their security notification service.

Schneider Electric strongly recommends the following industry cybersecurity best practices:

- Locate control and safety system networks and remote devices behind firewalls and isolate them from the business network.
- Install physical controls so no unauthorized personnel can access your industrial control and safety systems, components, peripheral equipment, and networks.
- Place all controllers in locked cabinets and never leave them in the 'Program' mode.
- Never connect programming software to any network other than the network intended for that device.
- Scan all methods of mobile data exchange with the isolated network such as CDs, USB drives, etc. before use in the terminals or any node connected to these networks.
- Never allow mobile devices that have connected to any other network besides the intended network to connect to the safety or control networks without proper sanitation.
- Minimize network exposure for all control system devices and systems and ensure that they are not accessible from the Internet.
- When remote access is required, use secure methods, such as virtual private networks (VPNs). Recognize that VPNs may have vulnerabilities and should be updated to the most current version available. Also, understand that VPNs are only as secure as the connected devices.
- For more information refer to the Schneider Electric recommended cybersecurity best practices document.

For more information, see Schneider Electric security notification 'SEVD-2024-345-03 Modicon M241 / M251 / M258 / LMC058'

Plugin Details

Severity: Critical

ID: 502809

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 12/19/2024

Updated: 4/2/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:schneider-electric:modicon_m251_series_firmware, cpe:/o:schneider-electric:modicon_lmc058_series_firmware, cpe:/o:schneider-electric:modicon_m241_series_firmware, cpe:/o:schneider-electric:modicon_m258_series_firmware

Required KB Items: Tenable.ot/Schneider

Exploit Ease: No known exploits are available

Patch Publication Date: 12/10/2024

Vulnerability Publication Date: 12/10/2024

Reference Information

CVE: CVE-2024-11737

CWE: 20

ICSA: 24-352-04

Detections

Analytics