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Fencer Intel
high 7.5

CVE-2020-6988 json

Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all version…

published 6y ago modified 4mo ago also EUVD-2020-28128

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
5.4%
EPSS 5.4% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all versions, RSLogix 500 Software v12.001 and prior, A remote, unauthenticated attacker can send a request from the RSLogix 500 software to the victim’s MicroLogix controller. The controller will then respond to the client with used password values to authenticate the user on the client-side. This method of authentication may allow an attacker to bypass authentication altogether, disclose sensitive information, or leak credentials.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-20-070-06 updated cvss 7.5

Rockwell Automation MicroLogix Controllers and RSLogix 500 Software

  • Rockwell Automation MicroLogix 1100 Controller Rockwell Automation RSLogix 500 Software <= 12.001 Rockwell Automation Series A Rockwell Automation Series B <= 21.001
    affected: mitigation “For MicroLogix 1400 series B controllers, Rockwell recommends affected users apply FRN 21.002 or later for MicroLogix 1400 Series B devices and use the enhanced password security feature.” compatibility.rockwellautomation.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5mo ago

Exploit prediction

5.42% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • n/a Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all versions, RSLogix 500 Software v12.001 and prior

Classification

Weakness
  • CWE-603 Use of Client-Side Authentication
  • CWE-287 Improper Authentication

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.