HOMEVULNERABILITIESCVE-2020-7566
HIGH

CVE-2020-7566

CWE-334Published: November 19, 2020· Updated: Jun 17, 2026

7.3
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-7566 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 7.3.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorAdjacent
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Affected Vendors & Products

schneider-electric2 product(s)
modicon m221 firmwaremodicon m221
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://us-cert.cisa.gov/ics/advisories/icsa-20-343-04
ADVISORYhttps://www.se.com/ww/en/download/document/SEVD-2020-315-05/
ADVISORYhttps://us-cert.cisa.gov/ics/advisories/icsa-20-343-04
ADVISORYhttps://www.se.com/ww/en/download/document/SEVD-2020-315-05/

All References (4)

→
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-04Third Party Advisory · US Government Resource
→
https://www.se.com/ww/en/download/document/SEVD-2020-315-05/Vendor Advisory
→
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-04Third Party Advisory · US Government Resource
→
https://www.se.com/ww/en/download/document/SEVD-2020-315-05/Vendor Advisory

Quick Facts

CVE IDCVE-2020-7566
CVSS Score7.3 / 10
SeverityHIGH
WeaknessCWE-334
CISA KEVNo
Affected1 vendor(s)
PublishedNov 19, 2020

Related CVEs (CWE-334)

CVE-2023-39979
9.8
CVE-2025-3895
9.1
CVE-2021-21955
7.5
CVE-2022-22517
7.5
CVE-2022-24402
7.5
CVE-2023-6951
6.6

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-7566 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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