CVE-2020-6998
highpriority · track · 35EPSS 0.032 · 88 %ileEURUUSEPSS · scored 2026-10-24
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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
No vendor fix yet; a mitigation is available.
- MitigationArmor Compact GuardLogix 5370 controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316 - MitigationArmor GuardLogix Safety Controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316 - MitigationCompact GuardLogix 5370 controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316 - MitigationCompactLogix 5370 L1 controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316 - MitigationCompactLogix 5370 L2 controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316 - MitigationCompactLogix 5370 L3 controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316 - MitigationControlLogix 5570 controllerscisa_csaf_ot
Rockwell Automation recommends affected users apply firmware v33.011 or later.
https://compatibility.rockwellautomation.com/Pages/MultiProductFindDownloads.aspx?crumb=112&refSoft=1&toggleState=&versions=59325,59316
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.3–8.6
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (37)
Products and version ranges known to be affected.
- Rockwell Automation Armor Compact GuardLogix 5370 controllers≤ unspecified ≤versions 33 and priorenisa_euvdEU
- Rockwell Automation Armor GuardLogix Safety Controllers≤ unspecified ≤versions 33 and priorenisa_euvdEU
- Rockwell Automation Compact GuardLogix 5370 controllers≤ unspecified ≤versions 33 and priorenisa_euvdEU
- Rockwell Automation CompactLogix 5370 L1 controllers≤ unspecified ≤versions 33 and priorenisa_euvdEU
- Rockwell Automation CompactLogix 5370 L2 controllers≤ unspecified ≤versions 33 and priorenisa_euvdEU
- Rockwell Automation CompactLogix 5370 L3 controllers≤ unspecified ≤versions 33 and priorenisa_euvdEU
advisories (1)
Vendor and ecosystem advisories describing this.
- ICSA-21-061-02Rockwell Automation CompactLogix 5370 and ControlLogix 5570 Controllers (Update A)2021-03-02icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability 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.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2020-6998/cnnvd
- https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1130398cnnvd
- https://us-cert.cisa.gov/ics/advisories/icsa-21-061-02cnnvd
- https://www.auscert.org.au/bulletins/ESB-2021.0784cnnvd
- https://www.cisa.gov/uscert/ics/advisories/icsa-21-061-02cnnvd
- https://www.rockwellautomation.com/en-id/products/hardware/allen-bradley.htmlPatchcnnvd
- https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1130398enisa_euvd
- https://www.cisa.gov/uscert/ics/advisories/icsa-21-061-02enisa_euvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan