SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-7833

An Improper Check for Unusual or Exceptional Conditions vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where an unauthenticated user can send a specially crafted XML data via a POST request to…

HIGH 7.5EPSS 1.38%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where an unauthenticated user can send a specially crafted XML data via a POST request to cause the web server to become unavailable

CVSS 3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.38% probability · 72th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-754
Affected
schneider-electric/modicom m340 firmware · schneider-electric/modicom premium firmware · schneider-electric/modicom quantum firmware · schneider-electric/modicom bmxnor0200h firmware
Source
cybersecurity@se.com
EPSS trend
0%3%5%27 October 2026: 1.38%27 October 202627 October 2026

EPSS 1.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.