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Full vulnerability report · 2022
CVE-2021-44521High confidence

Remote code execution for scripted UDFs

Apache Software Foundation · Apache Cassandra

9.1CriticalCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Critical technical impact and a public exploit reference; no CISA KEV confirmation is currently recorded. Verified remediation exists for at least one product or source, but 26 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 57.53% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Apache Software Foundation Apache Cassandra and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 26 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2021-44521 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitycassandra: RCE for scripted UDFs
26 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • cassandra as a component of Red Hat Fuse 7
  • cassandra as a component of Red Hat JBoss Data Grid 7
  • cassandra as a component of Red Hat JBoss Data Virtualization 6
  • cassandra as a component of Red Hat JBoss Enterprise Application Platform 6
  • jboss-on as a component of Red Hat JBoss Enterprise Application Platform 6
  • cassandra as a component of Red Hat JBoss Fuse 6
  • cassandra as a component of Red Hat JBoss Fuse Service Works 6
  • cassandra as a component of Red Hat JBoss Operations Network 3
  • org.jboss.on-jboss-on-parent as a component of Red Hat JBoss Operations Network 3
  • openshift3/metrics-cassandra as a component of Red Hat OpenShift Container Platform 3.11
  • openshift3/metrics-hawkular-metrics as a component of Red Hat OpenShift Container Platform 3.11
  • openshift3/metrics-schema-installer as a component of Red Hat OpenShift Container Platform 3.11
Summary
A flaw was found in Cassandra that allows users with certain permissions to execute user-defined functions to create scripts and run remote code execution. This flaw allows an attacker to gain unwanted access and also execute actions against Cassandra.
Remediation
Fix deferred
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-0915

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Critical technical impact and a public exploit reference; no CISA KEV confirmation is currently recorded. Verified remediation exists for at least one product or source, but 26 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

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.

What

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.

Why

Untrusted data can cross into a code-evaluation path and be interpreted as executable instructions.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

What

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.

Why

Untrusted data can cross into a code-evaluation path and be interpreted as executable instructions.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Improper Control of Generation of Code ('Code Injection') → execute code or commands in the affected security context
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-94 ↗

CWE-94: Improper Control of Generation of Code ('Code Injection'). The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-94Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20220216Security Bulletin 16 Feb 2022

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Feb 2022, published on 16 February 2022. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0004Multiples vulnérabilités dans IBM Sterling Global Mailbox

De multiples vulnérabilités ont été découvertes dans IBM Sterling. Elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance et un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2022-005568Apache Cassandra における重要なリソースに対する不適切なパーミッションの割り当てに関する脆弱性

Apache Cassandra には、重要なリソースに対する不適切なパーミッションの割り当てに関する脆弱性が存在します。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-5510Apache Cassandra 보안 업데이트 권고

Apache Cassandra에서 발생하는 원격코드실행 취약점(CVE-2021-44521)[1]

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 11 Feb 2022 · Last source change 4 Aug 2024, 04:25 UTC · CWE-94 · Improper Control of Generation of Code ('Code Injection')

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2022-0915
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    cassandra as a component of Red Hat Fuse 7; cassandra as a component of Red Hat JBoss Data Grid 7; cassandra as a component of Red Hat JBoss Data Virtualization 6; cassandra as a component of Red Hat JBoss Enterprise Application Platform 6; jboss-on as a component of Red Hat JBoss Enterprise Application Platform 6; cassandra as a component of Red Hat JBoss Fuse 6; cassandra as a component of Red Hat JBoss Fuse Service Works 6; cassandra as a component of Red Hat JBoss Operations Network 3; org.jboss.on-jboss-on-parent as a component of Red Hat JBoss Operations Network 3; openshift3/metrics-cassandra as a component of Red Hat OpenShift Container Platform 3.11; openshift3/metrics-hawkular-metrics as a component of Red Hat OpenShift Container Platform 3.11; openshift3/metrics-schema-installer as a component of Red Hat OpenShift Container Platform 3.11; openshift3/ose-metrics-cassandra as a component of Red Hat OpenShift Container Platform 3.11; openshift3/ose-metrics-hawkular-metrics as a component of Red Hat OpenShift Container Platform 3.11; openshift3/ose-metrics-schema-installer as a component of Red Hat OpenShift Container Platform 3.11; ocs4/ocs-must-gather-rhel8 as a component of Red Hat Openshift Container Storage 4; ocs4/ocs-rhel8-operator as a component of Red Hat Openshift Container Storage 4; ocs4/rook-ceph-rhel8-operator as a component of Red Hat Openshift Container Storage 4; odf-multicluster-operator-container as a component of Red Hat Openshift Container Storage 4; odf4/ocs-must-gather-rhel8 as a component of Red Hat Openshift Data Foundation 4; odf4/ocs-rhel9-operator as a component of Red Hat Openshift Data Foundation 4; odf4/odf-multicluster-rhel9-operator as a component of Red Hat Openshift Data Foundation 4; odf4/rook-ceph-rhel8-operator as a component of Red Hat Openshift Data Foundation 4; opendaylight.src as a component of Red Hat OpenStack Platform 10 (Newton); puppet-cassandra.src as a component of Red Hat OpenStack Platform 10 (Newton); puppet-cassandra.src as a component of Red Hat OpenStack Platform 13 (Queens)
    After
    cassandra as a component of Red Hat Fuse 7; cassandra as a component of Red Hat JBoss Data Grid 7; cassandra as a component of Red Hat JBoss Data Virtualization 6; cassandra as a component of Red Hat JBoss Enterprise Application Platform 6; jboss-on as a component of Red Hat JBoss Enterprise Application Platform 6; cassandra as a component of Red Hat JBoss Fuse 6; cassandra as a component of Red Hat JBoss Fuse Service Works 6; cassandra as a component of Red Hat JBoss Operations Network 3; org.jboss.on-jboss-on-parent as a component of Red Hat JBoss Operations Network 3; openshift3/metrics-cassandra as a component of Red Hat OpenShift Container Platform 3.11; openshift3/metrics-hawkular-metrics as a component of Red Hat OpenShift Container Platform 3.11; openshift3/metrics-schema-installer as a component of Red Hat OpenShift Container Platform 3.11; openshift3/ose-metrics-cassandra as a component of Red Hat OpenShift Container Platform 3.11; openshift3/ose-metrics-hawkular-metrics as a component of Red Hat OpenShift Container Platform 3.11; openshift3/ose-metrics-schema-installer as a component of Red Hat OpenShift Container Platform 3.11; ocs4/ocs-must-gather-rhel8 as a component of Red Hat Openshift Container Storage 4; ocs4/ocs-rhel8-operator as a component of Red Hat Openshift Container Storage 4; ocs4/rook-ceph-rhel8-operator as a component of Red Hat Openshift Container Storage 4; odf-multicluster-operator-container as a component of Red Hat Openshift Container Storage 4; odf4/ocs-must-gather-rhel8 as a component of Red Hat Openshift Data Foundation 4; odf4/ocs-rhel9-operator as a component of Red Hat Openshift Data Foundation 4; odf4/odf-multicluster-rhel9-operator as a component of Red Hat Openshift Data Foundation 4; odf4/rook-ceph-rhel9-operator as a component of Red Hat Openshift Data Foundation 4; opendaylight.src as a component of Red Hat OpenStack Platform 10 (Newton); puppet-cassandra.src as a component of Red Hat OpenStack Platform 10 (Newton); puppet-cassandra.src as a component of Red Hat OpenStack Platform 13 (Queens)
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Mitigation reference recorded
ENISA EUVD · EUVD-2022-0915↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-44521 · cve.blacktree.nl