CVE-2021-3583

Command injection via fact template evaluation

Published Sep 22, 2021 · Updated Aug 3, 2024

Ansible before 2.9.23 allows attackers to execute commands and disclose sensitive information through template injection in multiline YAML strings. The templating engine evaluates attacker-influenced Ansible facts embedded in multiline YAML templates when those facts contain template syntax, causing command execution during playbook processing. Exploitation requires local access to the Ansible controller and a playbook that uses the affected template pattern; impacts include disclosure of sensitive data and modification of controller-accessible data.

CVSS severity7.1
High
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Ansible before 2.9.23 allows attackers to execute commands and disclose sensitive information through template injection in multiline YAML strings. The templating engine evaluates attacker-influenced Ansible facts embedded in multiline YAML templates when those facts contain template syntax, causing command execution during playbook processing. Exploitation requires local access to the Ansible controller and a playbook that uses the affected template pattern; impacts include disclosure of sensitive data and modification of controller-accessible data.

The record

CVE
CVE-2021-3583
Published
Sep 22, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, CWE-94, T1059
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.1NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:N

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.

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No observations available

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

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-94Improper Control of Generation of Code ('Code Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

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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