Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-22681

CVE-2021-22681CRITICAL

n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers — Rockwell Multiple Products

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  H  H    9.8   .6363   99.2   YES

AFFECTED
  Product                                                                          Versions                               Fixed
  Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers  RSLogix 5000 Versions 16 through 20 –  —

TIMELINE
  Jan 5   Reserved by icscert
  Mar 3   Published (CNA: icscert)
  Mar 5   Added to CISA KEV, remediation due 2026-03-26

CWE-522 · CNA: icscert · CVSS v3.1 · 2 references · KEV due March 26, 2026

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
January 5, 2021	Reserved	Reserved by icscert
March 3, 2021	Published	Published (CNA: icscert)
March 5, 2026	KEV ADDED	Added to CISA KEV, remediation due 2026-03-26

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers	—	RSLogix 5000 Versions 16 through 20	—

Weaknesses

CWE-522

References (2)

https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03 [x_refsource_MISC]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22681 [government-resource]

Authoritative record: CVE-2021-22681 at cve.org

Weaknesses: CWE-522

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-22681 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.