What’s Vulnerable › Vulnerabilities

CVE-2021-32805: URL Redirection to Untrusted Site ('Open Redirect') in Flask-AppBuilder

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-09-08 · updated 2026-06-17
• Weakness: CWE-601

Description

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.

Affected products

• dpgaspar Flask-AppBuilder: before 3.3.2 — fixed in 3.3.2

How to fix

Upgrade to a fixed version: dpgaspar Flask-AppBuilder 3.3.2. Check the vendor advisory for mitigations.

References

• https://github.com/dpgaspar/Flask-AppBuilder/commit/6af28521589599b1dbafd6313256229ee9a4fa74
• https://github.com/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-624f-cqvr-3qw4
• https://github.com/dpgaspar/Flask-AppBuilder/commit/6af28521589599b1dbafd6313256229ee9a4fa74
• https://github.com/dpgaspar/Flask-AppBuilder/security/advisories/GHSA-624f-cqvr-3qw4

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