How severe is CVE-2021-22941?

CVE-2021-22941 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-22941?

Affected package information for CVE-2021-22941 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-22941?

No fixed version has been published for CVE-2021-22941 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-22941 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2021-22941, including 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-22941?

CVE-2021-22941 has an EPSS (Exploit Prediction Scoring System) score of 88.5%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2021-22941 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-22941 (Citrix ShareFile Improper Access Control Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-03-25. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-04-15. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-22941?

CVE-2021-22941 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2021-22941?

CVE-2021-22941 affects citrix sharefile storagezones controller. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2021-22941 published, and has it been updated?

CVE-2021-22941 was published on September 23, 2021 and was last updated on November 3, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-03-25 — agencies required to remediate by 2022-04-15 · Ransomware

CVE-2021-22941

CRITICAL

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.

Published

Sep 23, 2021

Updated

Nov 3, 2025

Affected

0 pkgs

Patched

None yet

Exploits

5 known

EPSS Exploitation Probability

via FIRST.org ↗

88.5%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

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.

Affected Products

1 product · 1 configurations

Application

sharefile storagezones controllercitrix

< 5.11.20

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Improper Access Control in Citrix ShareFile storage zones controller bef…

github.comGithubOct 2021

Improper Access Control in Citrix ShareFile storage zones controller bef…

github.comAPIOct 2021

Improper Access Control in Citrix ShareFile storage zones controller bef…

twitter.comAPISep 2021

Improper Access Control in Citrix ShareFile storage zones controller bef…

cisa.govCISAMar 2022

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2021-22941 in your stack?

O3 detects CVE-2021-22941 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my stack How O3 SCA works