CVE-2021-44521

Name: CVE-2021-44521
Creator: NVD / NIST
Published: 2022-02-11T13:15:07.907+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 54.89%

Last modified Jun 17, 2026

CVE-2021-44521 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. When running Apache Cassandra with the following configuration: enable_user_defined_functions: true enable_scripted_user_defined_functions: true enable_user_defined_functions_threads: false it is possible for an attacker to execute arbitrary code on the host. The attacker would need to have enough permissions to create user defined functions in the cluster to be able to exploit this. EPSS estimates a 54.89% chance of exploitation in the next 30 days.

Description

When running Apache Cassandra with the following configuration: enable_user_defined_functions: true enable_scripted_user_defined_functions: true enable_user_defined_functions_threads: false it is possible for an attacker to execute arbitrary code on the host. The attacker would need to have enough permissions to create user defined functions in the cluster to be able to exploit this. Note that this configuration is documented as unsafe, and will continue to be considered unsafe after this CVE.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

54.89%

98.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apache	Cassandra	>= 3.0.0, < 3.0.26
Apache	Cassandra	>= 3.11.0, < 3.11.12
Apache	Cassandra	>= 4.0.0, < 4.0.2

References

http://www.openwall.com/lists/oss-security/2022/02/11/4Mailing List, Third Party Advisory
https://jfrog.com/blog/cve-2021-44521-exploiting-apache-cassandra-user-defined-functions-for-remote-code-execution/Exploit, Mitigation, Third Party Advisory
https://lists.apache.org/thread/y4nb9s4co34j8hdfmrshyl09lokm7356Issue Tracking, Mailing List, Vendor Advisory
https://security.netapp.com/advisory/ntap-20220225-0001/Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/02/11/4Mailing List, Third Party Advisory
https://jfrog.com/blog/cve-2021-44521-exploiting-apache-cassandra-user-defined-functions-for-remote-code-execution/Exploit, Mitigation, Third Party Advisory
https://lists.apache.org/thread/y4nb9s4co34j8hdfmrshyl09lokm7356Issue Tracking, Mailing List, Vendor Advisory
https://security.netapp.com/advisory/ntap-20220225-0001/Third Party Advisory

Timeline

Published: Feb 11, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-44521?

How severe is CVE-2021-44521?

CVE-2021-44521 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 54.89% probability of exploitation in the next 30 days.

How do I fix CVE-2021-44521?

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-2021-44521?

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

Scan your code now

Source: NVD / NIST