CVE-2021-41254Public exploitNetwork attack vector

Authenticated cluster-admin escalation via Secret-backed shell injection

Published Nov 12, 2021 · Updated Aug 4, 2024

OS command injection in Flux CD Kustomize Controller before 0.15.0 allows remote authenticated users to gain cluster-admin privileges. During reconciliation, the controller places a Secret-supplied service-account token into a shell command without neutralizing metacharacters, causing injected commands to run inside its container. The path is limited to multitenant clusters where a non-admin can create Secrets, ServiceAccounts, and Flux Kustomizations, and execution uses the controller's Service Account.

CVSS severity8.8
High
EPSS probability1.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Flux CD Kustomize Controller before 0.15.0 allows remote authenticated users to gain cluster-admin privileges. During reconciliation, the controller places a Secret-supplied service-account token into a shell command without neutralizing metacharacters, causing injected commands to run inside its container. The path is limited to multitenant clusters where a non-admin can create Secrets, ServiceAccounts, and Flux Kustomizations, and execution uses the controller's Service Account.

The record

CVE
CVE-2021-41254
Published
Nov 12, 2021
Updated
Aug 4, 2024
Vendor
Flux CD
Product
Kustomize Controller
Classifications
CWE-78, T1068, T1059.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 12, 2021CVE 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

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Is a vulnerable build present?

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

  1. Affected versionversion=< 0.15.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Flux CD · Kustomize Controllerversion=< 0.15.0

Published CVSS scores

8.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1068Exploitation for Privilege Escalation
T1059.004Unix Shell

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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