CVE-2021-4041 is a high-severity (CVSS 7.8) Improper Input Validation vulnerability in ansible-runner. A fix is available for ansible-runner — see the affected versions and patch details below.
ansible-runner vulnerable to shell command injection
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2021-4041 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
ansible-runnerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
A flaw was found in ansible-runner. An improper escaping of the shell command, while calling the ansible_runner.interface.run_command, can lead to parameters getting executed as host's shell command. A developer could unintentionally write code that gets executed in the host rather than the virtual environment.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | ansible-runner | all versions | 2.1.0pip install --upgrade 'ansible-runner==2.1.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ansible-runner, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ansible-runner to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-4041 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-4041 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-4041. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Satellite 6.12 and later versions are not affected by this flaw.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.0 for RHEL 8 | ansible-runner-0:2.0.3-2.el8ap | RHSA-2022:0108 |
Frequently Asked Questions
Is CVE-2021-4041 in your dependencies?
O3 Security finds CVE-2021-4041 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.