SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-7791

A Permissions, Privileges, and Access Control vulnerability exists in Schneider Electric's Modicon M221 product (all references, all versions prior to firmware V1.6.2.0).

CRITICAL 9.8EPSS 1.90%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.90%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A Permissions, Privileges, and Access Control vulnerability exists in Schneider Electric's Modicon M221 product (all references, all versions prior to firmware V1.6.2.0). The vulnerability allows unauthorized users to overwrite the original password with their password. If an attacker exploits this vulnerability and overwrite the password, the attacker can upload the original program from the PLC.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
1.90% probability · 80th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-287, CWE-284
Affected
schneider-electric/modicon m221 firmware
Source
cybersecurity@se.com
EPSS trend
0%3%5%27 October 2026: 1.90%27 October 202627 October 2026

EPSS 1.9% 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.