How severe is CVE-2020-7539?

CVE-2020-7539 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-7539 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-7539?

CVE-2020-7539 primarily affects Schneider-electric Modicon M340 Bmxp341000 Firmware. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-7539?

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

When was CVE-2020-7539 published?

CVE-2020-7539 was published on 2020-12-11 and last updated on 2026-06-17.

CVE-2020-7539

CVE-2020-7539 is a high-severity vulnerability in Schneider-electric Modicon M340 Bmxp341000 Firmware with a CVSS 3.x base score of 7.5. 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-754.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-754
Affected product: Schneider-electric Modicon M340 Bmxp341000 Firmware
Published: 2020-12-11
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-7539?: 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.
How severe is CVE-2020-7539?: CVE-2020-7539 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-7539 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-7539?: CVE-2020-7539 primarily affects Schneider-electric Modicon M340 Bmxp341000 Firmware. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-7539?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-7539 published?: CVE-2020-7539 was published on 2020-12-11 and last updated on 2026-06-17.

References

https://www.se.com/ww/en/download/document/SEVD-2020-343-03/

Affected products (20)

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:bmxnoc0401_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:140cpu65150_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noe77111_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc78100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc78000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc77101_firmware:*:*:*:*:*:*:*:*

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