CVEPublished 2021-03-25Modified 2026-06-031 article on news5 live referencesNVD data

CVE-2021-22659Rockwellautomation · Micrologix_1400_firmware

Vulnerability data via NVD (ingested)

CVSS v3.1
8.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
EPSS percentile
72
Exploit Prediction Scoring System · top 28% of all CVEs
Description

Rockwell Automation MicroLogix 1400 Version 21.6 and below may allow a remote unauthenticated attacker to send a specially crafted Modbus packet allowing the attacker to retrieve or modify random values in the register. If successfully exploited, this may lead to a buffer overflow resulting in a denial-of-service condition. The FAULT LED will flash RED and communications may be lost. Recovery from denial-of-service condition requires the fault to be cleared by the user.

Timeline
Published 2021-03-25
Modified 2026-06-03

External references

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

More intel sources (5)

Known PoCs on GitHub

No public proof-of-concept repositories found for CVE-2021-22659 on GitHub.