CVE-2020-7539

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 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 a denial of service vulnerability when a specially crafted packet is sent to the controller over HTTP.

Affected products

Schneider-Electric 140Cpu65150 Firmware: before 6.1 — fixed in 6.1
Schneider-Electric 140Noc77101 Firmware: before 1.08 — fixed in 1.08
Schneider-Electric 140Noc78000 Firmware: before 1.74 — fixed in 1.74
Schneider-Electric 140Noc78100 Firmware: before 1.74 — fixed in 1.74
Schneider-Electric 140Noe77111 Firmware: before 7.1 — fixed in 7.1
Schneider-Electric Bmxnoc0401 Firmware: before 2.10 — fixed in 2.10
Schneider-Electric Bmxnoe0100 Firmware: before 3.3 — fixed in 3.3
Schneider-Electric Bmxnoe0110 Firmware: before 6.5 — fixed in 6.5
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: before 6.2 — fixed in 6.2
Schneider-Electric Tsxety5103 Firmware: before 6.4 — fixed in 6.4
Schneider-Electric Tsxp574634 Firmware: before 6.1 — fixed in 6.1
Schneider-Electric Tsxp575634 Firmware: before 6.1 — fixed in 6.1
Schneider-Electric Tsxp576634 Firmware: before 6.1 — fixed in 6.1

How to fix

Upgrade to a fixed version: Schneider-Electric 140Cpu65150 Firmware 6.1; Schneider-Electric 140Noc77101 Firmware 1.08; Schneider-Electric 140Noc78000 Firmware 1.74; Schneider-Electric 140Noc78100 Firmware 1.74; Schneider-Electric 140Noe77111 Firmware 7.1; Schneider-Electric Bmxnoc0401 Firmware 2.10; Schneider-Electric Bmxnoe0100 Firmware 3.3; Schneider-Electric Bmxnoe0110 Firmware 6.5; 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. Check the vendor advisory for mitigations.

References

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