CVE-2021-32805
URL Redirection to Untrusted Site ('Open Redirect') in Flask-AppBuilder
Flask-AppBuilder is an application development framework, built on top of Flask. In affected versions if using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability. To resolve this issue upgrade to Flask-AppBuilder 3.2.2 or above. If upgrading is infeasible users may filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting as a workaround.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
URL Redirection to Untrusted Site ('Open Redirect') in Flask-AppBuilder
Flask-AppBuilder is an application development framework, built on top of Flask. In affected versions if using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability. To resolve this issue upgrade to Flask-AppBuilder 3.2.2 or above. If upgrading is infeasible users may filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting as a workaround.
- Record
CVE-2021-32805- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
EUVDEUVD-2021-0081
Flask-AppBuilder is an application development framework, built on top of Flask. In affected versions if using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability. To resolve this issue upgrade to Flask-AppBuilder 3.2.2 or above. If upgrading is infeasible users may filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting as a workaround.
- Record
EUVD-2021-0081- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-624f-cqvr-3qw4
Flask-AppBuilder Open Redirect vulnerability
Impact
If using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability
Patches
Install Flask-AppBuilder 3.2.2 or above
Workarounds
Filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting
- Record
GHSA-624f-cqvr-3qw4- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
NVD
Flask-AppBuilder is an application development framework, built on top of Flask. In affected versions if using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability. To resolve this issue upgrade to Flask-AppBuilder 3.2.2 or above. If upgrading is infeasible users may filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting as a workaround.
- Record
CVE-2021-32805- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 5.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
OSV
Flask-AppBuilder is an application development framework, built on top of Flask. In affected versions if using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability. To resolve this issue upgrade to Flask-AppBuilder 3.2.2 or above. If upgrading is infeasible users may filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting as a workaround.
- Record
CVE-2021-32805- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-624f-cqvr-3qw4
Flask-AppBuilder Open Redirect vulnerability
Impact
If using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability
Patches
Install Flask-AppBuilder 3.2.2 or above
Workarounds
Filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting
- Record
GHSA-624f-cqvr-3qw4- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-601
- Updated
- 2026-11-02
OSVPYSEC-2021-359 No score
Flask-AppBuilder is an application development framework, built on top of Flask. In affected versions if using Flask-AppBuilder OAuth, an attacker can share a carefully crafted URL with a trusted domain for an application built with Flask-AppBuilder, this URL can redirect a user to a malicious site. This is an open redirect vulnerability. To resolve this issue upgrade to Flask-AppBuilder 3.2.2 or above. If upgrading is infeasible users may filter HTTP traffic containing ?next={next-site} where the next-site domain is different from the application you are protecting as a workaround.
- Record
PYSEC-2021-359- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
flask-appbuilderPyPI |
before 3.3.2 | 3.3.2 |
flask-appbuilderPyPI |
before 3.3.2, plus listed versions 0.1.100.1.110.1.120.1.130.1.14 Show 45 moreShow less0.1.150.1.160.1.170.1.180.1.190.1.200.1.210.1.220.1.230.1.240.1.250.1.260.1.270.1.280.1.290.1.30.1.330.1.340.1.350.1.360.1.370.1.380.1.40.1.430.1.440.1.450.1.460.1.470.1.50.1.60.1.70.1.80.1.90.10.00.10.10.10.20.10.30.10.40.10.50.10.60.10.70.2.00.2.10.2.20.3.0 |
3.3.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-32805 is a high vulnerability (CVSS 7.2) in Dpgaspar Flask-appbuilder, published September 8, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.70%, the 53rd percentile. Fixed in flask-appbuilder 3.3.2.
References
github.com/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-624f-cqvr-3qw4
nvd.nist.gov/vuln/detail/CVE-2021-32805
pypi.org/project/Flask-AppBuilder
Left out here: 192 versions. The JSON record has them.