CVE-2021-21956

Name: CVE-2021-21956
Creator: NVD / NIST
Published: 2022-04-14T20:15:08.607+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.27%

Last modified Jun 17, 2026

CVE-2021-21956 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. A php unserialize vulnerability exists in the Ai-Bolit functionality of CloudLinux Inc Imunify360 5.10.2. A specially-crafted malformed file can lead to potential arbitrary command execution. EPSS estimates a 1.27% chance of exploitation in the next 30 days.

Description

A php unserialize vulnerability exists in the Ai-Bolit functionality of CloudLinux Inc Imunify360 5.10.2. A specially-crafted malformed file can lead to potential arbitrary command execution. An attacker can provide a malicious file to trigger this vulnerability.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.27%

66.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cloudlinux	Imunify360	5.8
Cloudlinux	Imunify360	5.9
Cloudlinux	Imunify360	5.10.2

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1383Exploit, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1383Exploit, Third Party Advisory

Timeline

Published: Apr 14, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21956?

How severe is CVE-2021-21956?

CVE-2021-21956 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.27% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21956?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21956?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST