{"id":"CVE-2021-22659","state":"PUBLISHED","title":"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 o","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.","publishedAt":"2021-03-25T15:59:07.000Z","updatedAt":"2026-06-03T13:10:07.459Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"CISA-ADP"},"assigner":"icscert","products":["n/a Rockwell Automation MicroLogix 1400"],"affected":[{"vendor":"n/a","product":"Rockwell Automation MicroLogix 1400","versions":[{"version":"MicroLogix 1400, All series Version 21.6 and below","status":"affected"}]}],"references":["https://us-cert.cisa.gov/ics/advisories/icsa-21-033-01","https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight"],"weaknesses":["CWE-120"],"ingestedAt":"2026-10-29T19:48:02.192Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/22xxx/CVE-2021-22659.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-22659","state":"PUBLISHED","datePublished":"2021-03-25T15:59:07.000Z","dateUpdated":"2026-06-03T13:10:07.459Z","assignerShortName":"icscert","assignerOrgId":"7d14cffa-0d7d-4270-9dc0-52cabd5a23a6","dateReserved":"2021-01-05T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"n/a","product":"Rockwell Automation MicroLogix 1400","versions":[{"version":"MicroLogix 1400, All series Version 21.6 and below","status":"affected"}]}],"references":[{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-033-01","tags":["x_refsource_MISC"]},{"url":"https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight","tags":["x_refsource_MISC"]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-120","description":"CLASSIC BUFFER OVERFLOW CWE-120","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"icscert","dateUpdated":"2021-03-25T15:59:07.000Z","orgId":"7d14cffa-0d7d-4270-9dc0-52cabd5a23a6"},"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"ics-cert@hq.dhs.gov","ID":"CVE-2021-22659","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"Rockwell Automation MicroLogix 1400","version":{"version_data":[{"version_value":"MicroLogix 1400, All series Version 21.6 and below"}]}}]},"vendor_name":"n/a"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"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."}]},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CLASSIC BUFFER OVERFLOW CWE-120"}]}]},"references":{"reference_data":[{"name":"https://us-cert.cisa.gov/ics/advisories/icsa-21-033-01","refsource":"MISC","url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-033-01"},{"name":"https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight","refsource":"MISC","url":"https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight"}]}}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-033-01","tags":["x_refsource_MISC","x_transferred"]},{"url":"https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight","tags":["x_refsource_MISC","x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-03T18:51:07.020Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.5,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-06-03T13:09:27.807640Z","id":"CVE-2021-22659","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-03T13:10:07.459Z"}}]}}}