What’s Vulnerable › Vulnerabilities

CVE-2020-7549

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% 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 the Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions), that could cause denial of HTTP and FTP services when a series of specially crafted requests is sent to the controller over HTTP.

Affected products

• Schneider-Electric 140Cpu65150 Firmware: all versions
• Schneider-Electric 140Noc78000 Firmware: all versions
• Schneider-Electric 140Noc78100 Firmware: all versions
• Schneider-Electric 140Noe77111 Firmware: before 7.3 — fixed in 7.3
• Schneider-Electric Bmxnoc0401 Firmware: all versions
• Schneider-Electric Bmxnoe0100 Firmware: before 3.4 — fixed in 3.4
• Schneider-Electric Bmxnoe0110 Firmware: before 6.6 — fixed in 6.6
• 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
• Schneider-Electric Tsxety4103 Firmware: all versions
• Schneider-Electric Tsxety5103 Firmware: all versions
• Schneider-Electric Tsxp574634 Firmware: all versions
• Schneider-Electric Tsxp575634 Firmware: all versions
• Schneider-Electric Tsxp576634 Firmware: all versions

How to fix

Upgrade to a fixed version: Schneider-Electric 140Noe77111 Firmware 7.3; 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://www.se.com/ww/en/download/document/SEVD-2020-343-06/
• https://www.se.com/ww/en/download/document/SEVD-2020-343-06/

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