CVE-2021-22941
KEVRansomware UseCitrix ShareFile Improper Access Control Vulnerability
Description
Improper Access Control in Citrix ShareFile storage zones controller may allow an unauthenticated attacker to remotely compromise the storage zones controller.
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.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HPublishedSep 23, 2021
Last modifiedJun 17, 2026
Added to KEVMar 25, 2022
Remediation dueApr 15, 2022
References
- support.citrix.com/article/CTX328123Broken LinkVendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22941US Government Resource
0 recent articles mention this CVE
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Risk assessment · Critical
Actively exploited and used by ransomware crews. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1656 days
- Ransomware
- Used in known ransomware campaigns
- CVSS
- 9.8 CRITICAL
- EPSS (30-day exploit probability)
- 53.6% · top 1% of all CVEs
- Weakness
- CWE-284
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
- 5.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.