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No exploitation reported

CVE-2020-6111

No exploitation reported by the sources we read.

  • Published2020-12-03
  • WeaknessCWE-189

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An exploitable denial-of-service vulnerability exists in the IPv4 functionality of Allen-Bradley MicroLogix 1100 Programmable Logic Controller Systems Series B FRN 16.000, Series B FRN 15.002, Series B FRN 15.000, Series B FRN 14.000, Series B FRN 13.000, Series B FRN 12.000, Series B FRN 11.000 and Series B FRN 10.000. A specially crafted packet can cause a major error, resulting in a denial of service. An attacker can send a malicious packet to trigger this vulnerability.

Timeline

dates in UTC
  1. 2020-12-0313:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-6111?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-6111?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Rockwellautomation micrologix 1100 b firmwareversion to verify
BranchAffectedFixed in
10.0= 10.000no fix published
11.0= 11.000no fix published
12.0= 12.000no fix published
13.0= 13.000no fix published
14.0= 14.000no fix published
15.0= 15.000no fix published
15.2= 15.002no fix published
16.0= 16.000no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • ICSA-21-047-02 CISA1 known affected

    Rockwell Automation Allen-Bradley Micrologix 1100

    Allen-Bradley MicroLogix 1100: revision number 1.0

Full record on NVD

Fix

  1. Mitigation from the vendor CISA ICSA-21-047-02 · 1 productRockwell Automation recommends users of MicroLogix 1100 migrate to MicroLogix 1400 and apply firmware v21.006 or later. Please see Rockwell Automation's publication number, PN1548, for more information. Rockwell Automation recommends the following network-based vulnerability mitigations for embedde…
  2. Mitigation from the vendor CISA ICSA-21-047-02 · 1 productUtilize proper network infrastructure controls, such as firewalls, to help ensure traffic from unauthorized sources is blocked.
  3. Mitigation from the vendor CISA ICSA-21-047-02 · 1 productConsult the product documentation for specific features, such as a hardware key mode setting, to which may be used to block unauthorized changes, etc.
  4. Mitigation from the vendor CISA ICSA-21-047-02 · 1 productBlock all traffic to EtherNet/IP or other CIP protocol-based devices from outside the manufacturing zone by blocking or restricting access to TCP and UDP Port 2222 and Port 44818 using proper network infrastructure controls, such as firewalls, UTM devices, or other security appliances. For more inf…
  5. Mitigation from the vendor CISA ICSA-21-047-02 · 1 productMinimize network exposure for all control system devices and/or systems and ensure they are not accessible from the Internet. For further information about the risks of unprotected Internet accessible control systems, please see Knowledgebase Article ID PN715
  6. Mitigation from the vendor CISA ICSA-21-047-02 · 1 productLocate control system networks and devices behind firewalls and isolate them from the business network.

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.17.5read 2026-10-23
  • CNACVSS 3.07.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • CNAweakness (CWE)CWE-189read 2026-10-23
  • FIRST EPSSEPSS score5.6 %2026-10-23

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2020-12-03
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-6111?

An exploitable denial-of-service vulnerability exists in the IPv4 functionality of Allen-Bradley MicroLogix 1100 Programmable Logic Controller Systems Series B FRN 16.000, Series B FRN 15.002, Series B FRN 15.000, Series B FRN 14.000, Series B FRN 13.000, Series B FRN 12.000, Series B FRN 11.000 and Series B FRN 10.000. A specially crafted packet can cause a major error, resulting in a denial of service. An attacker can send a malicious packet to trigger this vulnerability.

Is CVE-2020-6111 actively exploited?

Active exploitation of CVE-2020-6111 has not been confirmed. Its EPSS score was 5.6% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-6111?

CVE-2020-6111 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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