CVE-2021-3583: A flaw was found in Ansible, where a user's controller is vulnerable to template injection

Q: How do I fix CVE-2021-3583?

ansible automation platform: downgrade or apply the listed mitigation; ansible engine: upgrade to 2.9.23; ansible tower: upgrade to 3.7.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-3583 being exploited?

CVE-2021-3583 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-3583 affect?

CVE-2021-3583 affects ansible automation platform, ansible engine, ansible tower. Severity is high (CVSS 7.1). A flaw was found in Ansible, where a user's controller is vulnerable to template injection. This issue can occur through facts used in the template if the user is trying to put templates in multi-line YAML strings and the facts being handle

Q: How urgent is CVE-2021-3583?

Priority 45/100. High severity; On your watchlist

This month

HIGH 7.1WATCHLISTDOWNGRADEUPGRADEUPGRADE

CVE-2021-3583 is a high-severity flaw (CVSS 7.1) affecting ansible automation platform, ansible engine, ansible tower. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in Ansible, where a user's controller is vulnerable to template injection. This issue can occur through facts used in the template if the user is trying to put templates in multi-line YAML strings and the facts being handled do not routinely include special template characters. This flaw allows attackers to perform command injection, which discloses sensitive information. The highest threat from this vulnerability is to confident

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-20, CWE-94
Published	2021-09-22
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-09-22 12:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

redhat ansible automation platform DOWNGRADE

Affected: 1.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.2

1. Check installed version

apt-cache policy ansible-automation-platform || rpm -q ansible-automation-platform || ansible-automation-platform --version

2. No fixed release: DOWNGRADE to a release before 1.2 (Debian / Ubuntu)

apt-cache madison ansible-automation-platform sudo apt install ansible-automation-platform=<VERSION_BEFORE_1.2> sudo apt-mark hold ansible-automation-platform

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list ansible-automation-platform sudo dnf downgrade ansible-automation-platform-<VERSION_BEFORE_1.2> sudo dnf versionlock add ansible-automation-platform

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat ansible engine UPGRADE

Affected: < 2.9.23

Fixed in: 2.9.23

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ansible-engine || rpm -q ansible-engine || ansible-engine --version

2. UPGRADE to 2.9.23 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ansible-engine

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ansible-engine

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

redhat ansible tower UPGRADE

Affected: < 3.7.0

Fixed in: 3.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ansible-tower || rpm -q ansible-tower || ansible-tower --version

2. UPGRADE to 3.7.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ansible-tower

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ansible-tower

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-3583?

ansible automation platform: downgrade or apply the listed mitigation; ansible engine: upgrade to 2.9.23; ansible tower: upgrade to 3.7.0. Exact commands for each OS are on this page.

Is CVE-2021-3583 being exploited?

CVE-2021-3583 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-3583 affect?

CVE-2021-3583 affects ansible automation platform, ansible engine, ansible tower. Severity is high (CVSS 7.1). A flaw was found in Ansible, where a user's controller is vulnerable to template injection. This issue can occur through facts used in the template if the user is trying to put templates in multi-line YAML strings and the facts being handle

How urgent is CVE-2021-3583?

Priority 45/100. High severity; On your watchlist

Software pages

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References

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