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Fencer Intel
medium 5.8

CVE-2020-6998 json

Rockwell Automation CompactLogix 5370 and ControlLogix 5570 Controllers Improper Input Validation

published 4y ago modified 4mo ago also EUVD-2020-28138

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.2%
EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

The connection establishment algorithm found in Rockwell Automation CompactLogix 5370 and ControlLogix 5570 versions 33 and prior does not sufficiently manage its control flow during execution, creating an infinite loop. This may allow an attacker to send specially crafted CIP packet requests to a controller, which may cause denial-of-service conditions in communications with other products.

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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-21-061-02 updated cvss 5.8

Rockwell Automation CompactLogix 5370 and ControlLogix 5570 Controllers (Update A)

  • Rockwell Automation Armor Compact GuardLogix 5370 controllers <= 33 Rockwell Automation Armor GuardLogix Safety Controllers <= 33 Rockwell Automation Compact GuardLogix 5370 controllers <= 33 Rockwell Automation CompactLogix 5370 L1 controllers <= 33 Rockwell Automation CompactLogix 5370 L2 controllers <= 33 Rockwell Automation CompactLogix 5370 L3 controllers <= 33
    +1 more products
    Rockwell Automation ControlLogix 5570 controllers <= 33
    affected: mitigation “Rockwell Automation recommends affected users apply firmware v33.011 or later.” 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
last yr.

Exploit prediction

3.16% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
NVD 3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected products

  • Rockwell Automation Armor Compact GuardLogix 5370 controllers
  • Rockwell Automation Armor GuardLogix Safety Controllers
  • Rockwell Automation CompactLogix 5370 L1 controllers
  • Rockwell Automation CompactLogix 5370 L2 controllers
  • Rockwell Automation CompactLogix 5370 L3 controllers
  • Rockwell Automation Compact GuardLogix 5370 controllers
  • Rockwell Automation ControlLogix 5570 controllers

Classification

Weakness
  • CWE-20 Improper Input Validation

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.