SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-23393

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.

MEDIUM 5.4EPSS 0.72%

Does this matter?

Lower severity and a low EPSS score (0.72%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS
0.72% probability · 52th percentile
CISA KEV
Not listed
Weakness
CWE-601
Affected
flask unchained project/flask unchained
Source
report@snyk.io

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.