CVE-2021-44521Public exploitNetwork attack vector

Authenticated code execution via scripted UDF sandbox escape

Published Feb 11, 2022 · Updated Aug 4, 2024

Code injection in Apache Cassandra allows remote authenticated users to execute arbitrary host code through scripted user-defined functions. With UDF threads disabled, Nashorn JavaScript can reach java.lang.System, remove the security manager, and invoke Runtime.exec without the intended sandbox restrictions. Exploitation requires CREATE FUNCTION permission and the non-default combination of enabled UDFs, enabled scripted UDFs, and disabled UDF threads.

CVSS severity9.1
Critical
EPSS probability55.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Code injection in Apache Cassandra allows remote authenticated users to execute arbitrary host code through scripted user-defined functions. With UDF threads disabled, Nashorn JavaScript can reach java.lang.System, remove the security manager, and invoke Runtime.exec without the intended sandbox restrictions. Exploitation requires CREATE FUNCTION permission and the non-default combination of enabled UDFs, enabled scripted UDFs, and disabled UDF threads.

The record

CVE
CVE-2021-44521
Published
Feb 11, 2022
Updated
Aug 4, 2024
Vendor
The Apache Software Foundation
Product
Apache Cassandra
Classifications
CWE-94, CWE-732, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.0.0 <unspecified
  2. Affected versionversion=3.1 <unspecified
  3. Affected versionversion=4.0.0 <unspecified
  4. Affected versionversion=unspecified <3.0.26
  5. Affected versionversion=unspecified <3.11.12
  6. Affected versionversion=unspecified <4.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Cassandraversion=3.0.0 <unspecified; version=3.1 <unspecified; version=4.0.0 <unspecified; version=unspecified <3.0.26; version=unspecified <3.11.12; version=unspecified <4.0.2

Published CVSS scores

9.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
8.5NIST National Vulnerability DatabaseAV:N/AC:M/Au:S/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-732Incorrect Permission Assignment for Critical Resource
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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