CVE-2021-23393

    Dashboard / Vulnerabilities / CVE-2021-23393

    CVE-2021-23393

    Published: 11 Jun 2021Last Modified: 9 Jul 2026

    Summary:

    Details: 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.

    References: https://github.com/briancappello/flask-unchained/commit/71e36b28166f9ffbe0a991f51127f0984f7e6a40, https://snyk.io/vuln/SNYK-PYTHON-FLASKUNCHAINED-1293189

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -f282da7b65eb9644cc0d0b1b4c11e74ca04f9dd3

    Affected versions

    v0.8.1
    v0.8.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2021-23393 | CVE-DB