Vulnerability · Published Jul 5, 2021 · Assigned by snyk
CVE-2021-23401Open Redirect
Medium 5.4
In plain English
A medium-severity security flaw in Flask-User. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 66% of all known vulnerabilities).
Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)1.1%top 33.8% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | flask-user | no fix listed | GHSA-4298-89hc-6rfv |
| PyPI | flask-user | no fix listed | PYSEC-2021-337 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| n/a | Flask-User | 0 – before unspecified |
References
- https://snyk.io/vuln/SNYK-PYTHON-FLASKUSER-1293188 x_refsource_MISC
- https://github.com/lingthio/Flask-User x_refsource_MISC
- https://github.com/lingthio/Flask-User/blob/master/flask_user/user_manager__utils.py x_refsource_MISC