GHSA-j8fq-86c5-5v2r: Duplicate Advisory Remote Code Execution Vulnerability

CRITICAL
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CVSS 9.8
CWE-668
Published
Advisory Summary

GHSA-j8fq-86c5-5v2r is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-668: Exposure of Resource to Wrong Sphere) affecting Duplicate Advisory libraries in the PyPI ecosystem. The issue involves remote code execution in dask. Remediation is available by upgrading affected packages to version 2021.10.0.

GHSA-j8fq-86c5-5v2r at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-j8fq-86c5-5v2r
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-668: Exposure of Resource to Wrong Sphere
Affected Product Duplicate Advisory
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 GHSA-j8fq-86c5-5v2r

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

dask fixed: 2021.10.0 
pip install dask>=2021.10.0
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 dask

How to Check if You Are Affected

To determine whether your Python environment is affected by GHSA-j8fq-86c5-5v2r, inspect your installed packages using pip:

pip show dask

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2021.10.0), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-668: Exposure of Resource to Wrong Sphere, where the product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource. In Duplicate Advisory, 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

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-hwqr-f3v9-hwxr. This link is maintained to preserve external references. ## Original Description An issue was discovered in Dask (aka python-dask) through 2021.09.1. Single machine Dask clusters started with dask.distributed.LocalCluster or dask.distributed.Client (which defaults to using LocalCluster) would mistakenly configure their respective Dask workers to listen on external interfaces (typically with a randomly selected high port) rather than only on localhost. A Dask cluster created using this method (when running on a machine that has an applicable port exposed) could be used by a sophisticated attacker to achieve remote code execution.

GHSA-j8fq-86c5-5v2r Affected Duplicate Advisory Versions

1 component(s)
Fixed Versions:
2021.10.0
Product / Package Ecosystem Affected Versions Fixed Version
dask
pypi/dask
PyPI
< 2021.10.0
2021.10.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/dask/distributed/security/advisories/GHSA-hwqr-f3v9-hwxr
NVD — GHSA-j8fq-86c5-5v2r NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-42343
Duplicate Advisory Source Repository REPOSITORY
https://github.com/dask/distributed/pull/5427
Security Fix Commit FIX COMMIT
https://github.com/dask/distributed/commit/afce4be8e05fb180e50a9d9e38465f1a82295e1b
docs.dask.org/en/latest/changelog... WEB
https://docs.dask.org/en/latest/changelog.html
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-j8fq-86c5-5v2r
Duplicate Advisory Source Repository REPOSITORY
https://github.com/dask/dask/tags
Duplicate Advisory Source Repository REPOSITORY
https://github.com/dask/distributed
Duplicate Advisory Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/dask/PYSEC-2021-387.yaml

Frequently Asked Questions

What is GHSA-j8fq-86c5-5v2r?
GHSA-j8fq-86c5-5v2r is a security vulnerability in Duplicate Advisory involving Remote code execution in dask under CWE-668: Exposure of Resource to Wrong Sphere.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to 2021.10.0 across affected packages: dask.
What version fixes GHSA-j8fq-86c5-5v2r?
Upgrading to 2021.10.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is dask affected?
Yes, dask is affected in releases prior to 2021.10.0. Upgrade your dependency to 2021.10.0 or later.
What is the CVSS score of GHSA-j8fq-86c5-5v2r?
GHSA-j8fq-86c5-5v2r 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 GHSA-j8fq-86c5-5v2r?
GHSA-j8fq-86c5-5v2r is classified under CWE-668: Exposure of Resource to Wrong Sphere (The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.).
How can I check PyPI dependencies for GHSA-j8fq-86c5-5v2r?
Run the dependency tree command: 'pip show dask'. 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-j8fq-86c5-5v2r",
  "modified" : "2026-02-03T17:37:28Z",
  "published" : "2021-10-27T18:53:48Z",
  "withdrawn" : "2026-02-03T17:37:27Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Remote code execution in dask",
  "details" : "## Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-hwqr-f3v9-hwxr. This link is maintained to preserve external references.\n\n## Original Description\nAn issue was discovered in Dask (aka python-dask) through 2021.09.1. Single machine Dask clusters started with dask.distributed.LocalCluster or dask.distributed.Client (which defaults to using LocalCluster) would mistakenly configure their respective Dask workers to listen on external interfaces (typically with a randomly selected high port) rather than only on localhost. A Dask cluster created using this method (when running on a machine that has an applicable port exposed) could be used by a sophisticated attacker to achieve remote code execution.",
  "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" : "dask"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2021.10.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/dask/distributed/security/advisories/GHSA-hwqr-f3v9-hwxr"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-42343"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dask/distributed/pull/5427"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dask/distributed/commit/afce4be8e05fb180e50a9d9e38465f1a82295e1b"
  }, {
    "type" : "WEB",
    "url" : "https://docs.dask.org/en/latest/changelog.html"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-j8fq-86c5-5v2r"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dask/dask/tags"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dask/distributed"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/dask/PYSEC-2021-387.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-668" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-27T18:16:11Z",
    "nvd_published_at" : "2021-10-26T11:15:00Z"
  }
}