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Fencer Vulns
high 7.5

CVE-2020-7549 json

A CWE-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists in the Web Server on Modicon M340, Legacy Offers Modic…

published 2020-12-11 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-28674

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

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.

Patch / fix

  • 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
  • schneider-electric bmxnoe0100_firmware 3.4
  • schneider-electric bmxnoe0110_firmware 6.6
  • schneider-electric 140noe77111_firmware 7.3

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

1.10% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • n/a Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions)

Classification

Weakness
  • CWE-754 Improper Check for Unusual or Exceptional Conditions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.