Open Redirect in Flask-Security Project
CVE-2021-23385
This affects all versions of package Flask-Security. When using the get_post_logout_redirect and get_post_login_redirect functions, 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. 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. **Note:** Flask-Security is not maintained anymore.
Vulnerability class: Open Redirect
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.012 (67.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 67.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.012 · change: +0.001
Affected products
- Flask-Security Project
- Flask-Security — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security.snyk.io/vuln/SNYK-PYTHON-FLASKSECURITY-1293234 (Exploit, Third Party Advisory)
- github.com/mattupstate/flask-security (Product, Third Party Advisory)
- snyk.io/blog/url-confusion-vulnerabilities/ (Technical Description, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2023/08/msg00034.html (mailing-list)
Frequently asked questions
- What is CVE-2021-23385?
- CVE-2021-23385 is a medium-severity vulnerability in Flask-Security Project, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2022-08-02.
- How severe is CVE-2021-23385?
- Medium severity. CVSS v3 base score is 5.4 out of 10.
- Is CVE-2021-23385 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.