CVE-2021-29621

mediumpriority · track · 22EPSS 0.034 · 89 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
3.40% (89th) EPSS
CVSS 5 · medium
Is it mine?
5 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

5.3
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.05mediumAV:N/AC:L/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · ENISA EU
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · security-advisories@github.comexploitability 3.9 · impact 1.4
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Nsecondary · OSV
v3.14.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-203USprimaryCWE-203US
03

affected products (5)

Products and version ranges known to be affected.

04

advisories (3)

Vendor and ecosystem advisories describing this.

  • GHSA-434h-p4gx-jm89Observable Response Discrepancy in Flask-AppBuilder2021-05-27ghsa · osvUS

    ### Impact 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. ### Patches Upgrade to 3.3.0 ### For more information If you have any questions or comments about this advisory: * Open an issue in [Flask-AppBuilder](https://github.com/dpgaspar/Flask-AppBuilder)

  • BIT-airflow-2021-29621Observable Response Discrepancy in Flask-AppBuilder2024-03-06vendor · osvUS

    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.

  • PYSEC-2021-902021-06-07vendor · osvUS

    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.

05

also known as (7)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvnvdNVDCVE.orgMITRE
published 2021-06-07modified 2026-06-17
08

references (18)

External citations — patches, advisories, analysis.

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