IRONSMITHINTEL
CRITICALCVSS9.8
|
Actively Exploited
|CISA KEV|CVE-2021-22941|Auth: none — unauthenticated|Reboot: required|Manual only

Citrix ShareFile Improper Access Control Vulnerability (CVE-2021-22941)

Improper Access Control in Citrix ShareFile storage zones controller may allow an unauthenticated attacker to remotely compromise the storage zones controller.

Published Sep 23, 2021 · Updated May 17, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2022-04-15 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Software Vulnerability (CWE-284) (CWE-284) vulnerability in Citrix ShareFile. Improper Access Control in Citrix ShareFile storage zones controller before 5.11.20 may allow an unauthenticated attacker to remotely compromise the storage zones controller. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

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Phishing link

→

🖼

Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●Network Security Team
●Firewall Administrators
●IT Security
●Running sharefile storagezones controller: v < 5.11.20
Real-world incidentsWhat we've seen

CISA confirms this CVE has been used in known ransomware campaigns. Added to the KEV catalog on 2022-03-25; federal agencies required to remediate by 2022-04-15.

How to patch

Manual remediation steps

1
Identify affected hosts: query inventory for network-security installs in scope.
2
Apply the vendor security update referenced in CVE-2021-22941's advisory. No specific KB/version is encoded yet — consult the linked MSRC/vendor URL.
3
Verify the fix per the vendor's published verification steps.
4
Document the remediation in your change ticket and re-scan with your vulnerability scanner to confirm closure.
PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2021-22941↗ MSRC Advisory↗ NVD↗ Vendor Advisory