CVE-2021-4041: Ansible runner Ansible-runner Vulnerable To Shell Command Vulnerability

HIGH
Advisory Identifier: GHSA-6j58-grhv-2769
Share
CVSS 7.8
CWE-116 CWE-20
Published
Advisory Summary

CVE-2021-4041 is a HIGH (CVSS 7.8) ansible-runner vulnerable to shell command vulnerability (CWE-116: Improper Encoding or Escaping of Output) affecting Ansible runner libraries in the PyPI ecosystem. The issue involves ansible-runner vulnerable to shell command injection. Remediation is available by upgrading affected packages to version 2.1.0.

CVE-2021-4041 at a Glance

CVE Identifier CVE-2021-4041
GHSA Identifier GHSA-6j58-grhv-2769
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-116: Improper Encoding or Escaping of Output
Affected Product Ansible runner
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.8

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

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-4041

To remediate this vulnerability, upgrade all affected Ansible runner 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-runner fixed: 2.1.0 
pip install ansible-runner>=2.1.0
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-runner

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2021-4041, inspect your installed packages using pip:

pip show ansible-runner

Analyze the terminal output to locate any version of Ansible runner in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.1.0), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-116: Improper Encoding or Escaping of Output, where the product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. as a result, the intended structure of the message is not preserved. In Ansible runner, 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 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.

CVE-2021-4041 Affected Ansible runner Versions

1 component(s)
Fixed Versions:
2.1.0
Product / Package Ecosystem Affected Versions Fixed Version
ansible-runner
pypi/ansible-runner
PyPI
< 2.1.0
2.1.0

References

NVD — CVE-2021-4041 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-4041
Security Fix Commit FIX COMMIT
https://github.com/ansible/ansible-runner/commit/3533f265f4349a3f2a0283158cd01b59a6bbc7bd
Ansible runner Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2021-4041
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2028074
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-6j58-grhv-2769
Ansible runner Source Repository REPOSITORY
https://github.com/ansible/ansible-runner
Ansible runner Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/ansible-runner/PYSEC-2022-253.yaml

Frequently Asked Questions

What is CVE-2021-4041?
CVE-2021-4041 is a security vulnerability in Ansible runner involving ansible-runner vulnerable to shell command injection under CWE-116: Improper Encoding or Escaping of Output.
Which Ansible runner versions are affected?
Affected versions include releases prior to 2.1.0 across affected packages: ansible-runner.
What version fixes CVE-2021-4041?
Upgrading to 2.1.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ansible-runner affected?
Yes, ansible-runner is affected in releases prior to 2.1.0. Upgrade your dependency to 2.1.0 or later.
What is the CVSS score of CVE-2021-4041?
CVE-2021-4041 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-4041?
CVE-2021-4041 is classified under CWE-116: Improper Encoding or Escaping of Output (The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.).
How can I check PyPI dependencies for CVE-2021-4041?
Run the dependency tree command: 'pip show ansible-runner'. 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-6j58-grhv-2769",
  "modified" : "2024-09-03T21:16:19Z",
  "published" : "2022-08-25T00:00:27Z",
  "aliases" : [ "CVE-2021-4041" ],
  "summary" : "ansible-runner vulnerable to shell command injection",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ansible-runner"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-4041"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ansible/ansible-runner/commit/3533f265f4349a3f2a0283158cd01b59a6bbc7bd"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2021-4041"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2028074"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-6j58-grhv-2769"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ansible/ansible-runner"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/ansible-runner/PYSEC-2022-253.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-116", "CWE-20" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-09-01T22:22:11Z",
    "nvd_published_at" : "2022-08-24T16:15:00Z"
  }
}