CVE-2020-6984Network attack vector

Unauthenticated controller access via discoverable password cipher

Published Mar 16, 2020 · Updated Jun 3, 2026

Broken password protection in Rockwell Automation MicroLogix and RSLogix 500 allows remote attackers to access controllers. The products protect device passwords with a discoverable cryptographic function, exposing the method used to derive protected password values; Rockwell has not published algorithm-level details. No authentication or user interaction is required, and successful exploitation grants controller access, although published material does not identify the available controller actions.

CVSS severity9.8
Critical
EPSS probability2.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Broken password protection in Rockwell Automation MicroLogix and RSLogix 500 allows remote attackers to access controllers. The products protect device passwords with a discoverable cryptographic function, exposing the method used to derive protected password values; Rockwell has not published algorithm-level details. No authentication or user interaction is required, and successful exploitation grants controller access, although published material does not identify the available controller actions.

The record

CVE
CVE-2020-6984
Published
Mar 16, 2020
Updated
Jun 3, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-327, T0859
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 16, 2020CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
9.8Rockwell AutomationCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-327Use of a Broken or Risky Cryptographic Algorithm
T0859Valid Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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