CVE-2021-29621 json
Observable Response Discrepancy in Flask-AppBuilder
published 2021-05-27 5 y ago modified 2026-09-08 2 mo ago also BIT-airflow-2021-29621 , EUVD-2021-0083 , GHSA-434h-p4gx-jm89 , PYSEC-2021-90
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 3.4%
- EPSS 3.4% chance of exploitation in 30 days, percentile 88%
- public exploits
- 0
- none known
Summary
Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder <= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.
Patch / fix
- pypi flask-appbuilder 3.3.0
- bitnami airflow 1.10.1
Exploit prediction
3.40% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:P/I:N/A:N |
| OSV | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | flask-appbuilder | <3.3.0 |
3.3.0 |
| bitnami | airflow | >=1.10.0, <1.10.1 |
1.10.1 |
Affected products
- dpgaspar Flask-AppBuilder
Classification
- Weakness
-
- CWE-203 Observable Discrepancy
References
-
github.com
/dpgaspar/Flask-AppBuilder/commit/780bd0e8fbf2d36ada52edb769477e0a4edae580
web, patch, third-party-advisory, advisory
-
github.com
/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-434h-p4gx-jm89
web, third-party-advisory, advisory
-
pypi.org
/project/Flask-AppBuilder/
product, third-party-advisory, advisory, package
-
lists.apache.org
/thread.html/r5b754118ba4e996adf03863705d34168bffec202da5c6bdc9bf3add5%40%3Cannounce.apache.org%3E
mailing-list, web
-
lists.apache.org
/thread.html/r466759f377651f0a690475d5a52564d0e786e82c08d5a5730a4f8352%40%3Cannounce.apache.org%3E
mailing-list, web
-
lists.apache.org
/thread.html/r91067f953906d93aaa1c69fe2b5472754019cc6bd4f1ba81349d62a0%40%3Ccommits.airflow.apache.org%3E
mailing-list, web
-
nvd.nist.gov
/vuln/detail/CVE-2021-29621
advisory, web
-
github.com
/dpgaspar/Flask-AppBuilder
package
-
github.com
/pypa/advisory-database/tree/main/vulns/flask-appbuilder/PYSEC-2021-90.yaml
web
-
lists.apache.org
/thread.html/r466759f377651f0a690475d5a52564d0e786e82c08d5a5730a4f8352@%3Cannounce.apache.org%3E
web
-
lists.apache.org
/thread.html/r5b754118ba4e996adf03863705d34168bffec202da5c6bdc9bf3add5@%3Cannounce.apache.org%3E
web
-
lists.apache.org
/thread.html/r91067f953906d93aaa1c69fe2b5472754019cc6bd4f1ba81349d62a0@%3Ccommits.airflow.apache.org%3E
web
-
pypi.org
/project/Flask-AppBuilder
web
Sources
- CVE List CVE-2021-29621
- GitHub Advisory GHSA-434h-p4gx-jm89
- NVD CVE-2021-29621
- OSV BIT-airflow-2021-29621
- OSV PYSEC-2021-90
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.