How severe is CVE-2020-7540?

CVE-2020-7540 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-7540 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-7540?

CVE-2020-7540 primarily affects Schneider-electric Modicon M340 Bmxp341000 Firmware. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-7540?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-7540 published?

CVE-2020-7540 was published on 2020-12-11 and last updated on 2026-06-17.

CVE-2020-7540

CVE-2020-7540 is a critical-severity vulnerability in Schneider-electric Modicon M340 Bmxp341000 Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-306
Affected product: Schneider-electric Modicon M340 Bmxp341000 Firmware
Published: 2020-12-11
Last modified: 2026-06-17

Description

A CWE-306: Missing Authentication for Critical Function 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 unauthenticated command execution in the controller when sending special HTTP requests.

Frequently asked questions

What is CVE-2020-7540?: A CWE-306: Missing Authentication for Critical Function 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 unauthenticated command execution in the controller when sending special HTTP requests.
How severe is CVE-2020-7540?: CVE-2020-7540 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-7540 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-7540?: CVE-2020-7540 primarily affects Schneider-electric Modicon M340 Bmxp341000 Firmware. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-7540?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-7540 published?: CVE-2020-7540 was published on 2020-12-11 and last updated on 2026-06-17.

References

https://www.se.com/ww/en/download/document/SEVD-2020-343-04/

Affected products (23)

cpe:2.3:o:schneider-electric:modicon_m340_bmxp341000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_bmxp342000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_bmxp3420102_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_bmxp3420102cl_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_bmxp342020_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_bmxp3420302_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:modicon_m340_bmxp3420302cl_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:bmxnoe0100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:bmxnoe0110_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noe77101_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noe77111_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140cpu65150_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140cpu65160_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc78000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc78100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc77101_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxp574634_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxp575634_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxp576634_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxety4103_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxety5103_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:bmxnoc0401_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:bmxnor200h_firmware:*:*:*:*:*:*:*:*

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