{"id":"CVE-2021-22681","published":"2021-03-03T18:15:14Z","modified":"2026-06-17T03:37:34Z","title":"Rockwell Multiple Products Insufficient Protected Credentials Vulnerability","vendor":"Rockwell","product":"Multiple Products","tier":"core","eol":null,"description":{"text":"Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800. Rockwell Automation Studio 5000 Logix Designer Versions 21 and later and RSLogix 5000: Versions 16 through 20 are vulnerable because an unauthenticated attacker could bypass this verification mechanism and authenticate with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800.","provenance":"source","from":"NVD"},"summary":{"text":"Rockwell Automation Studio 5000 Logix Designer (Versions 21 and later) and RSLogix 5000 (Versions 16 through 20) contain an insufficiently protected credentials flaw in the key-based mechanism that verifies communication between the engineering software and Logix controllers such as CompactLogix, ControlLogix, DriveLogix, GuardLogix, and SoftLogix. An unauthenticated network-reachable attacker can bypass this verification and authenticate to the listed controllers, with no user interaction or prior credentials required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:12:02Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.6363,"percentile":0.99213,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2026-03-05","dueDate":"2026-03-26","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://support.rockwellautomation.com/app/answers/answer_view/a_id/1130301/~/cve-2021-22681%3A-authentication-bypass-vulnerability-found-in-logix-controllers- ; https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-03 ; https://nvd.nist.gov/vuln/detail/CVE-2021-22681","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-03-05","exploitedFirstSeen":"2026-03-05","ransomware":false,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-03-05"},{"url":"https://www.tenable.com/blog/what-to-know-about-cyberav3ngers-the-irgc-linked-group-targeting-critical-infrastructure","date":"2026-04-09"},{"url":"https://cyble.com/blog/monthly-threat-landscape-march-2026/","date":"2026-04-20"},{"url":"https://thecyberexpress.com/march-2026-threat-landscape/","date":"2026-04-22"}],"evidenceTotal":4,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-522","name":"Insufficiently Protected Credentials"}],"references":[{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03","tags":["Third Party Advisory","US Government Resource"]},{"url":"https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03","tags":["Third Party Advisory","US Government Resource"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22681","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: unauthenticated remote exploitation of exposed controller communication","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"an unauthenticated attacker could bypass this verification mechanism","start":507,"end":575}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: bypass yields authenticated access to controllers","mappingType":"primary_impact","evidence":[{"from":"description","quote":"could bypass this verification mechanism and authenticate with Rockwell Automation","start":535,"end":617}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-9817","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-9817","exploited":true,"exploitedSince":"2026-03-05","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2026-07-31","earliestUrl":"https://github.com/pcrosby-1990/cip-security-poc","repos":[{"name":"pcrosby-1990/cip-security-poc","url":"https://github.com/pcrosby-1990/cip-security-poc","stars":0,"created":"2026-07-31"}]},"first":{"date":"2026-07-31","source":"PoC-in-GitHub","url":"https://github.com/pcrosby-1990/cip-security-poc"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1078"],"provenance":"ai"}],"timeline":[{"date":"2021-03-03","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-22681","provenance":"source"},{"date":"2026-03-05","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","provenance":"source"},{"date":"2026-03-05","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2026-03-05","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-9817","provenance":"source"},{"date":"2026-07-31","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/pcrosby-1990/cip-security-poc","provenance":"source"}],"speed":{"daysToPublicExploit":1976,"firstExploitFrom":"PoC-in-GitHub","daysToKev":1828},"priority":{"score":74.7,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":5.0,"detail":"added 238 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.84,"detail":"percentile 0.9921"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 PoC-in-GitHub repo"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.86,"detail":"base score 9.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}