What’s Vulnerable › Vulnerabilities

CVE-2020-7536

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-12-11 · updated 2026-06-17
• Weakness: CWE-754

Description

A CWE-754:Improper Check for Unusual or Exceptional Conditions vulnerability exists in Modicon M340 CPUs (BMXP34* versions prior to V3.30) Modicon M340 Communication Ethernet modules (BMXNOE0100 (H) versions prior to V3.4 BMXNOE0110 (H) versions prior to V6.6 BMXNOR0200H all versions), that could cause the device to be unreachable when modifying network parameters over SNMP.

Affected products

• Schneider-Electric Bmxnoe0100 Firmware: before 3.4 — fixed in 3.4
• Schneider-Electric Bmxnoe0110 Firmware: before 6.6 — fixed in 6.6
• Schneider Electric SE BMXNOR0200H Ethernet / Serial RTU module: all versions
• Schneider-Electric Modicon M340 Bmxp341000 Firmware: before 3.30 — fixed in 3.30
• Schneider-Electric Modicon M340 Bmxp342000 Firmware: before 3.30 — fixed in 3.30
• Schneider-Electric Modicon M340 Bmxp3420102 Firmware: before 3.30 — fixed in 3.30
• Schneider-Electric Modicon M340 Bmxp3420102Cl Firmware: before 3.30 — fixed in 3.30
• Schneider-Electric Modicon M340 Bmxp342020 Firmware: before 3.30 — fixed in 3.30
• Schneider-Electric Modicon M340 Bmxp3420302 Firmware: before 3.30 — fixed in 3.30
• Schneider-Electric Modicon M340 Bmxp3420302Cl Firmware: before 3.30 — fixed in 3.30

How to fix

Upgrade to a fixed version: Schneider-Electric Bmxnoe0100 Firmware 3.4; Schneider-Electric Bmxnoe0110 Firmware 6.6; Schneider-Electric Modicon M340 Bmxp341000 Firmware 3.30; Schneider-Electric Modicon M340 Bmxp342000 Firmware 3.30; Schneider-Electric Modicon M340 Bmxp3420102 Firmware 3.30; Schneider-Electric Modicon M340 Bmxp3420102Cl Firmware 3.30; Schneider-Electric Modicon M340 Bmxp342020 Firmware 3.30; Schneider-Electric Modicon M340 Bmxp3420302 Firmware 3.30; Schneider-Electric Modicon M340 Bmxp3420302Cl Firmware 3.30. Check the vendor advisory for mitigations.

References

• https://security.cse.iitk.ac.in/responsible-disclosure
• https://www.se.com/ww/en/download/document/SEVD-2020-343-07/
• https://security.cse.iitk.ac.in/responsible-disclosure
• https://www.se.com/ww/en/download/document/SEVD-2020-343-07/

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