SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-7830

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where a denial of service can occur for ~1 minute by sending…

HIGH 7.5EPSS 2.42%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability exists in the embedded web servers in all Modicon M340, Premium, Quantum PLCs and BMXNOR0200 where a denial of service can occur for ~1 minute by sending a specially crafted HTTP request.

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
2.42% probability · 84th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-113
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: 2.42%27 October 202627 October 2026

EPSS 2.4% 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.