7.3

CVE-2020-7566: schneider-electric modicon_m221_firmware Small Space of Random Values

CVSS: 7.3v3.1HighModified
Published 19-11-2020Last modified 29-05-2026
Open JSON

Vulnerability summary

CVE-2020-7566 is a high (CVSS 7.3) Small Space of Random Values vulnerability in schneider-electric modicon_m221_firmware. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 20.9% of scored vulnerabilities.

Overall risk
29/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.3/10
010
High · v3.1 (NVD)
EPSS score
0.30%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 19-11-2020
    PublishedVulnerability first disclosed.
  2. 29-05-2026
    Last modifiedVulnerability information updated.

Description

A CWE-334: Small Space of Random Values vulnerability exists in Modicon M221 (all references, all versions) that could allow the attacker to break the encryption keys when the attacker has captured the traffic between EcoStruxure Machine - Basic software and Modicon M221 controller.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

0.00 pp

From 0.30% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.30%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Schneider-electric1 product

1 vendor · 1 product

References

2 links