`CVE-2021-44521` Apache Cassandra

Affected software	Apache Cassandra
Severity	9.1 Critical CVSS 3.1 2 scores
Fixed in	`3.0.26`, `3.11.12`, `4.0.2`
Weakness	Code injection (CWE-94)
Published	11 Feb 2022
Updated	17 Jun 2026

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.

CWE-732 · Incorrect permission assignment

Exploitation status

Working exploit published

A reviewed exploit catalogue lists ready-to-run exploit code for this CVE.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment no assessment published
Indexed PoC 3 indexed Published artifacts you can open, in GitHub PoC, Nuclei; first seen 2022-02-24.
EPSS 59% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99% of all scored CVEs.

1 of these are GitHub repositories with fewer than 5 stars. They are listed for reference and don't count toward the exploitation status above.

Index	Artifact	Stars	First seen
GitHub PoC	Automated PoC of CVE-2021-44521	10	2022-02-24
GitHub PoC	full PoC of CVE-2021-44521	1	2022-12-03
Nuclei	Apache Cassandra Load UDF RCE

Waratek protection

Protected by Waratek

Waratek has a rule that blocks attacks on this vulnerability.

Protection full
Action available security rule
Review human Researcher
Record active

Decided by	Manual classification of this CVE in the legacy dataset
Finding	A manual classification set this CVE's status to Protected by Waratek.

Decided by

Manual classification of this CVE in the legacy dataset

Finding

A manual classification set this CVE's status to Protected by Waratek.

How to mitigate CVE-2021-44521

Upgrade Apache Cassandra to a release that fixes it: 3.0.26, 3.11.12 or 4.0.2. Until you can, Waratek RASP blocks exploitation with a security rule that blocks this kind of attack. It runs inside the Java application, with no code changes.

Waratek RASP Runtime protection for Java applications

CVSS

9.1 CRITICAL v3.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 9.1 CRITICAL CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H NVD Primary published

CVSS 2.0 8.5 none AV:N/AC:M/Au:S/C:C/I:C/A:C NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	9.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`	NVD	Primary	published
CVSS 2.0	8.5	none	`AV:N/AC:M/Au:S/C:C/I:C/A:C`	NVD	Primary

Affected software and releases

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

org.apache.cassandra:cassandra-all 0 3.0.26 unbounded

org.apache.cassandra:cassandra-all 3.11.0 3.11.12 unbounded

org.apache.cassandra:cassandra-all 4.0.0 4.0.2 unbounded

Package	Introduced	Fixed	Last affected
`org.apache.cassandra:cassandra-all`	0	`3.0.26`	unbounded
`org.apache.cassandra:cassandra-all`	3.11.0	`3.11.12`	unbounded
`org.apache.cassandra:cassandra-all`	4.0.0	`4.0.2`	unbounded

Products and versions

2 products, 6 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	apache	cassandra	generic	≥ 3.0.0 and ＜ 3.0.26 · ≥ 3.11.0 and ＜ 3.11.12 · ≥ 4.0.0 and ＜ 4.0.2
osv	org.apache.cassandra	cassandra-all	generic	＜ 3.0.26 · ≥ 3.11.0 and ＜ 3.11.12 · ≥ 4.0.0 and ＜ 4.0.2

Source

Vendor

Product

Scheme

Affected versions

nvd

apache

cassandra

generic

≥ 3.0.0 and ＜ 3.0.26 · ≥ 3.11.0 and ＜ 3.11.12 · ≥ 4.0.0 and ＜ 4.0.2

osv

org.apache.cassandra

cassandra-all

generic

＜ 3.0.26 · ≥ 3.11.0 and ＜ 3.11.12 · ≥ 4.0.0 and ＜ 4.0.2

References

URL	Tags
https://github.com/apache/cassandra	PACKAGE
https://issues.apache.org/jira/browse/CASSANDRA-17352	WEB
https://jfrog.com/blog/cve-2021-44521-exploiting-apache-cassandra-user-defined-functions-for-remote-code-execution	WEB
https://lists.apache.org/thread/y4nb9s4co34j8hdfmrshyl09lokm7356	WEB
https://security.netapp.com/advisory/ntap-20220225-0001	WEB
http://www.openwall.com/lists/oss-security/2022/02/11/4	WEB
https://jfrog.com/blog/cve-2021-44521-exploiting-apache-cassandra-user-defined-functions-for-remote-code-execution/	Exploit, Mitigation, Third Party Advisory
https://security.netapp.com/advisory/ntap-20220225-0001/	Third Party Advisory

URL

Timeline

Published	2022-02-11	By the CVE Program.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.

Published

2022-02-11

By the CVE Program.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

How VRT decided (5 of 24 rules ran)

5 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification decided it matched Protected by Waratek Found in legacy manual classifications

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

NVD ↗ · CVE.org ↗