CVE•Published 2021-07-09•Modified 2026-06-03•1 article on news•6 live references•NVD data
CVE-2021-33012Rockwellautomation · Micrologix_1100_firmware
Vulnerability data via NVD (ingested)
CVSS v3.1
8.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS percentile
86
Exploit Prediction Scoring System · top 14% of all CVEs
Weaknesses (CWE)
Description
Rockwell Automation MicroLogix 1100, all versions, allows a remote, unauthenticated attacker sending specially crafted commands to cause the PLC to fault when the controller is switched to RUN mode, which results in a denial-of-service condition. If successfully exploited, this vulnerability will cause the controller to fault whenever the controller is switched to RUN mode.
Timeline
Published 2021-07-09
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).
Shodan · vuln tag0 hosts
vuln:CVE-2021-33012Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · OS
os:"Micrologix 1100 Firmware"Hosts Shodan identified as running Micrologix 1100 Firmware.
More intel sources (5)
Shodan report
vuln:CVE-2021-33012Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2021-33012Censys host search filtered to this CVE id.
grep.app
CVE-2021-33012Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2021-33012GitHub code search for direct mentions.
Google dork
"CVE-2021-33012" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.