CVE-2021-43857: Gerapy Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-9w7f-m4j4-j3xw
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CVSS 9.8
CWE-78
Published
Advisory Summary

CVE-2021-43857 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Gerapy libraries in the PyPI ecosystem. The issue involves gerapy may cause remote code execution. Remediation is available by upgrading affected packages to version 0.9.8.

CVE-2021-43857 at a Glance

CVE Identifier CVE-2021-43857
GHSA Identifier GHSA-9w7f-m4j4-j3xw
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Product Gerapy
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

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

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

How to Fix CVE-2021-43857

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

gerapy fixed: 0.9.8 
pip install gerapy>=0.9.8
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 gerapy

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2021-43857, inspect your installed packages using pip:

pip show gerapy

Analyze the terminal output to locate any version of Gerapy in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.9.8), your application is affected.

Note: The pip show gerapy 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 Gerapy, 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

### Impact project_configure function exist remote code execute in Gerapy < 0.9.8 ### Patches Patched in version 0.9.8, please install with: ``` pip3 install -U gerapy ```

CVE-2021-43857 Affected Gerapy Versions

1 component(s)
Fixed Versions:
0.9.8
Product / Package Ecosystem Affected Versions Fixed Version
gerapy
pypi/gerapy
PyPI
< 0.9.8
0.9.8

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Gerapy/Gerapy/security/advisories/GHSA-9w7f-m4j4-j3xw
NVD — CVE-2021-43857 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-43857
Gerapy Source Repository REPOSITORY
https://github.com/Gerapy/Gerapy/issues/219
Security Fix Commit FIX COMMIT
https://github.com/Gerapy/Gerapy/commit/49bcb19be5e0320e7e1535f34fe00f16a3cf3b28
Gerapy Source Repository REPOSITORY
https://github.com/Gerapy/Gerapy
Gerapy Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/gerapy/PYSEC-2021-867.yaml
Gerapy Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/gerapy/PYSEC-2022-228.yaml
Gerapy Security Information SECURITY
http://packetstormsecurity.com/files/165459/Gerapy-0.9.7-Remote-Code-Execution.html

Frequently Asked Questions

What is CVE-2021-43857?
CVE-2021-43857 is a security vulnerability in Gerapy involving Gerapy may cause remote code execution under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').
Which Gerapy versions are affected?
Affected versions include releases prior to 0.9.8 across affected packages: gerapy.
What version fixes CVE-2021-43857?
Upgrading to 0.9.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is gerapy affected?
Yes, gerapy is affected in releases prior to 0.9.8. Upgrade your dependency to 0.9.8 or later.
What is the CVSS score of CVE-2021-43857?
CVE-2021-43857 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-43857?
CVE-2021-43857 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-2021-43857?
Run the dependency tree command: 'pip show gerapy'. 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-9w7f-m4j4-j3xw",
  "modified" : "2024-09-20T17:52:44Z",
  "published" : "2022-01-06T17:36:38Z",
  "aliases" : [ "CVE-2021-43857" ],
  "summary" : "Gerapy may cause remote code execution",
  "details" : "### Impact\n\nproject_configure function exist remote code execute in Gerapy < 0.9.8\n\n### Patches\n\nPatched in version 0.9.8, please install with:\n\n```\npip3 install -U gerapy\n```",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "gerapy"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.9.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Gerapy/Gerapy/security/advisories/GHSA-9w7f-m4j4-j3xw"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-43857"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Gerapy/Gerapy/issues/219"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Gerapy/Gerapy/commit/49bcb19be5e0320e7e1535f34fe00f16a3cf3b28"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Gerapy/Gerapy"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/gerapy/PYSEC-2021-867.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/gerapy/PYSEC-2022-228.yaml"
  }, {
    "type" : "WEB",
    "url" : "http://packetstormsecurity.com/files/165459/Gerapy-0.9.7-Remote-Code-Execution.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-78" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-01-05T20:42:01Z",
    "nvd_published_at" : "2021-12-27T19:15:00Z"
  }
}