Ansible EngineApplication · Redhat
CVE-2020-1734
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA flaw was found in the pipe lookup plugin of ansible. Arbitrary commands can be run, when the pipe lookup plugin uses subprocess.Popen() with shell=True, by overwriting ansible facts and the variable is not escaped by quote plugin. An attacker could take advantage and run arbitrary commands by overwriting the ansible facts.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThe Ansible pipe lookup plugin uses subprocess.Popen() with shell=True, which combined with the ability to overwrite Ansible facts (variables) without proper escaping by the quote plugin, allows an attacker to inject arbitrary shell commands through crafted fact values.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Ansible EngineApplication
<= 2.7.16= 2.8.8= 2.9.5
Ansible TowerApplication
<= 3.3.4= 3.4.5= 3.5.5= 3.6.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- High
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Ansible Engine or Tower versionRun 'ansible --version' or check Tower UI for version information under Settings > Tower > License or AboutAffected if Version is Ansible Engine <= 2.7.16, = 2.8.8, = 2.9.5, or Tower <= 3.3.4, = 3.4.5, = 3.5.5, = 3.6.3 (note: user provided 2.4.5 but pattern suggests 3.4.5)
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Locate the pipe lookup plugin source fileFind the lookup plugin file - typically at 'lib/ansible/plugins/lookup/pipe.py' in the Ansible installation directory or within the ansible package in site-packagesAffected if The file exists in the affected Ansible version installations
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Verify subprocess.Popen uses shell=TrueOpen the pipe.py lookup plugin file and inspect the code for subprocess.Popen calls, checking whether shell=True parameter is presentAffected if The code contains 'subprocess.Popen' with 'shell=True' in the pipe lookup plugin
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Determine if custom facts or variables can be injectedCheck if playbooks, roles, or inventories allow user-controlled variables to be set as Ansible facts without validation (look for set_fact tasks or variable injection points)Affected if Users can define or overwrite Ansible facts/variables that could be passed to the pipe lookup plugin
Environment is affected if running a vulnerable Ansible version and the pipe lookup plugin with shell=True is present, allowing arbitrary shell command injection through controllable Ansible facts.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataReplace shell=True with shell=False in subprocess.Popen() calls within the pipe lookup plugin and ensure all user-controlled variables are properly escaped/quoted before being passed to the subprocess.
Fix this in Ansible Engine
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-1734 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-1734 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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