CVSS 3.1
6.1 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NCVE-2021-23401
Medium (6.1) in flask-user project flask-user. EPSS 1.1% chance of exploitation in the next 30 days.
This affects all versions of package Flask-User. When using the make_safe_url function, it is possible to bypass URL validation and redirect a user to an arbitrary URL by providing multiple back slashes such as /////evil.com/path or \\\evil.com/path. This vulnerability is only exploitable if an alternative WSGI server other than Werkzeug is used, or the default behaviour of Werkzeug is modified using 'autocorrect_location_header=False.
Severity
- EPSS
- 1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)
- CWE
- CWE-601
- Published
- Modified
- Record from
- the NVD, synced
Affected
- flask-user_project:flask-user
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-4298-89hc-6rfv | PyPI | flask-user | <=1.0.2.2 | no fix published |
| PYSEC-2021-337 | PyPI | flask-user | all versions | no fix published |