Open Redirect in Flask Unchained Project
CVE-2021-23393
This affects the package Flask-Unchained before 0.9.0. When using the the _validate_redirect_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. 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.
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: 0.007 (52.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- Flask Unchained Project
- Flask-Unchained — versions unspecified
Weakness classification (CWE)
References
- snyk.io/vuln/SNYK-PYTHON-FLASKUNCHAINED-1293189 (Patch, Third Party Advisory)
- github.com/briancappello/flask-unchained/commit/71e36b28166f9ffbe0a991f51127f09… (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-23393?
- CVE-2021-23393 is a medium-severity vulnerability in Flask Unchained Project, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.4/10. Published 2021-06-11.
- How severe is CVE-2021-23393?
- Medium severity. CVSS v3 base score is 5.4 out of 10.