{"id":"CVE-2021-33012","aliases":["EUVD-2021-19733","GHSA-m5fq-q49w-wc2j"],"status":"published","title":"Rockwell Automation MicroLogix 1100, all versions, allows a remote, unauthenticated attacker...","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.","severity":{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.02637,"percentile":0.85687,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2021-07-09T14:03:55Z","modified":"2026-06-17T03:54:00Z","products":[{"vendor":"rockwellautomation","product":"micrologix_1100_firmware"}],"references":[{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-189-01","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33012"},{"url":"https://github.com/advisories/GHSA-m5fq-q49w-wc2j"}],"sources":{"cve":[{"id":"CVE-2021-33012","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.","status":"published","published":"2021-07-09T14:03:55Z","modified":"2026-06-03T13:18:00.338Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:33:10.204494Z"}],"euvd":[{"id":"EUVD-2021-19733","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.","status":"published","published":"2021-07-09T14:03:55Z","modified":"2026-06-03T13:18:00Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T18:20:54.727632Z"}],"ghsa":[{"id":"GHSA-m5fq-q49w-wc2j","title":"Rockwell Automation MicroLogix 1100, all versions, allows a remote, unauthenticated attacker...","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.","status":"published","published":"2022-05-24T19:07:20Z","modified":"2026-06-03T15:30:34Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:08:30.717444Z"}],"nvd":[{"id":"CVE-2021-33012","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.","status":"published","published":"2021-07-09T15:15:08.503Z","modified":"2026-06-17T03:54:00.5Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:06:55.259633Z"}]}}