October 13, 2026

CVE Watchtower

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CVE-2021-22681NVD

Vulnerability Summary

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.
Severity Level
UNKNOWN
Published Date
Mar 3, 2021
Last Modified
Mar 6, 2026
Exploitation Status
ACTIVE
EPSS Score (30-Day)
12.91%Probability
Root Weakness (CWE)
CWE-522: Unknown/Unlisted Weakness ↗
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.

Affected & Patched Versions

Affected Versions
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= RSLogix 5000 Versions 16 through 20
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= Studio 5000 Logix Designer: Versions 21 and later
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= CompactLogix 1768, 1769, 5370, 5380, 5480
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= ControlLogix 5550, 5560, 5570, 5580
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= DriveLogix 5560, 5730, 1794-L34
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= Compact GuardLogix 5370, 5380
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= GuardLogix 5570, 5580
  • n/a Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers >= SoftLogix 5800
Patched Versions
Not provided by cveorg for this CVE.
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🎁7-Day Free Trial — Try Pro or Team, no card required.
📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
📈EPSS Spike Alerts — Catch rising risk before it peaks.
🎯Custom EPSS/CVSS — Filter noise, focus on risk.
🛡️Exploit Intel — A 2nd confirmed-exploit signal beyond KEV.
🐙GitHub Issues — Auto-tracked, no duplicates.
📬Weekly Digest — One clean summary, not inbox spam.
🏷️Watchlist Groups — Tag alerts by team (Infra/AppSec/SOC).
💬Webhooks — Slack & Teams integration.
🔀Smart Routing — Critical alerts to one channel, rest to another.
🚫Ad-Free — Uninterrupted experience.

External References