Authentication Bypass in Rockwell Automation Logix Controllers
CVE-2021-22681 affects Rockwell Automation Studio 5000 Logix Designer versions 21 and later and RSLogix 5000 versions 16 through 20 in their trust relationship with multiple Logix controller families, including CompactLogix, ControlLogix, GuardLogix, DriveLogix, and SoftLogix. The software uses a key-based mechanism to verify that Logix controllers are communicating with legitimate Rockwell engineering software. The vulnerability exists because this key is insufficiently protected and can be discovered or extracted, allowing an unauthenticated attacker to bypass the verification mechanism and authenticate to affected controllers as if they were an authorized workstation or application. Rockwell and CISA reporting indicate that successful exploitation can enable an unauthorized third-party tool or application to connect to the controller and interact with it as a trusted engineering endpoint.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
33 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An older Rockwell Automation vulnerability that the company confirmed has been exploited in the wild.
A critical authentication bypass vulnerability in Rockwell Automation Logix controllers that allows attackers with an intercepted cryptographic key to connect to affected PLCs without valid credentials.
A vulnerability affecting Rockwell operational technology products that U.S. agencies say is being exploited in campaigns targeting internet-facing OT devices, including PLC environments.
A Rockwell Automation vulnerability involving insufficient protection of credentials affecting multiple products.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.