Exploited vulnerability · CISA KEV

Is CVE-2021-22941 exploited? Yes: in CISA KEV since 25 Mar 2022

Gociux · Citrix ShareFile · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-22941, Citrix ShareFile Improper Access Control Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 25 Mar 2022, 183 days after it was published. It is known to be used in ransomware campaigns. It affects Citrix ShareFile, an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

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

What to do

1. Check whether you run it. Look for ShareFile in your asset inventory, including appliances and cloud images. Stack check lists every exploited Citrix CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 23 Sep 2021.
4. Get told next time. Email alerts when CISA adds a CVE for Citrix.

References

• nvd.nist.gov/vuln/detail/CVE-2021-22941

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in March 2022 · Citrix scorecard · act-now radar.