CVE-2020-1734: Ansible OS Command Injection Vulnerability

HIGH
Advisory Identifier: GHSA-h39q-95q5-9jfp
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CVSS 7.4
CWE-78
Published
Advisory Summary

CVE-2020-1734 is a HIGH (CVSS 7.4) os command injection vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Ansible libraries in the PyPI ecosystem. The issue involves os command injection in ansible. Remediation is available by upgrading affected packages to version 2.10.0rc1, 2.9.11, 2.8.13.

CVE-2020-1734 at a Glance

CVE Identifier CVE-2020-1734
GHSA Identifier GHSA-h39q-95q5-9jfp
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Product Ansible
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L).

Attack Vector Local (AV:L)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2020-1734

To remediate this vulnerability, upgrade all affected Ansible dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ansible fixed: 2.10.0rc1 
pip install ansible>=2.10.0rc1
ansible fixed: 2.9.11 
pip install ansible>=2.9.11
ansible fixed: 2.8.13 
pip install ansible>=2.8.13
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show ansible

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2020-1734, inspect your installed packages using pip:

pip show ansible

Analyze the terminal output to locate any version of Ansible in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.10.0rc1), your application is affected.

Note: The pip show ansible command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), where the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component. In Ansible, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A 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.

CVE-2020-1734 Affected Ansible Versions

3 component(s)
Fixed Versions:
2.10.0rc12.9.112.8.13
Product / Package Ecosystem Affected Versions Fixed Version
ansible
pypi/ansible
PyPI
≥ 2.10.0a1
< 2.10.0rc1
2.10.0rc1
ansible
pypi/ansible
PyPI
≥ 2.9.0a1
< 2.9.11
2.9.11
ansible
pypi/ansible
PyPI
< 2.8.13
2.8.13

References

NVD — CVE-2020-1734 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-1734
Ansible Source Repository REPOSITORY
https://github.com/ansible/ansible/issues/67792
Ansible Source Repository REPOSITORY
https://github.com/ansible/ansible/issues/70159
Ansible Source Repository REPOSITORY
https://github.com/ansible/ansible/pull/70596
Security Fix Commit FIX COMMIT
https://github.com/ansible/ansible/commit/4f978af4ca16ad9828ffe42203b9615425195f8b
Security Fix Commit FIX COMMIT
https://github.com/ansible/ansible/commit/963bdd9983b91a48fb6949fb2ef41071e72d0be0
Security Fix Commit FIX COMMIT
https://github.com/ansible/ansible/commit/bff0724e9eab2770f874e018298f9ab74cc2a78f
Security Fix Commit FIX COMMIT
https://github.com/ansible/ansible/commit/e5649ca3e807f17e7c034ee22791f107162973b0
access.redhat.com/errata/rhba-2020:05... WEB
https://access.redhat.com/errata/RHBA-2020:0547
access.redhat.com/errata/rhba-2020:15... WEB
https://access.redhat.com/errata/RHBA-2020:1539
Ansible Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2020-1734
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1801804
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1734
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-h39q-95q5-9jfp
Ansible Source Repository REPOSITORY
https://github.com/ansible/ansible
Ansible Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/ansible/PYSEC-2020-6.yaml

Frequently Asked Questions

What is CVE-2020-1734?
CVE-2020-1734 is a security vulnerability in Ansible involving OS Command Injection in ansible under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').
Which Ansible versions are affected?
Affected versions include releases prior to 2.10.0rc1, 2.9.11, 2.8.13 across affected packages: ansible.
What version fixes CVE-2020-1734?
Upgrading to 2.10.0rc1, 2.9.11, 2.8.13 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ansible affected?
Yes, ansible is affected in releases prior to 2.10.0rc1, 2.9.11, 2.8.13. Upgrade your dependency to 2.10.0rc1, 2.9.11, 2.8.13 or later.
What is the CVSS score of CVE-2020-1734?
CVE-2020-1734 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L.
What CWE is associated with CVE-2020-1734?
CVE-2020-1734 is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.).
How can I check PyPI dependencies for CVE-2020-1734?
Run the dependency tree command: 'pip show ansible'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h39q-95q5-9jfp",
  "modified" : "2024-09-10T22:22:28Z",
  "published" : "2022-02-09T00:11:19Z",
  "aliases" : [ "CVE-2020-1734" ],
  "summary" : "OS Command Injection in ansible",
  "details" : "A 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ansible"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.10.0a1"
      }, {
        "fixed" : "2.10.0rc1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ansible"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.9.0a1"
      }, {
        "fixed" : "2.9.11"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ansible"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.8.13"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-1734"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/issues/67792"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/issues/70159"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/pull/70596"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/commit/4f978af4ca16ad9828ffe42203b9615425195f8b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/commit/963bdd9983b91a48fb6949fb2ef41071e72d0be0"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/commit/bff0724e9eab2770f874e018298f9ab74cc2a78f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible/commit/e5649ca3e807f17e7c034ee22791f107162973b0"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHBA-2020:0547"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHBA-2020:1539"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2020-1734"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1801804"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1734"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-h39q-95q5-9jfp"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ansible/ansible"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/ansible/PYSEC-2020-6.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-02T18:38:15Z",
    "nvd_published_at" : "2020-03-03T22:15:00Z"
  }
}