Cyber Resilience

CVE-2021-23393

Medium

Published: 11 June 2021

Published
11 June 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS Score 0.0020 42.0th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23393 is a medium-severity Open Redirect (CWE-601) vulnerability in Flask Unchained Project Flask Unchained. Its CVSS base score is 5.4 (Medium).

Operationally, ranked at the 42.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability 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…

more

exploitable if an alternative WSGI server other than Werkzeug is used, or the default behaviour of Werkzeug is modified using 'autocorrect_location_header=False.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

flask unchained project
flask unchained
≤ 0.9.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-601

Security awareness includes verifying URLs and avoiding untrusted redirects that lead to malicious sites.

addresses: CWE-601

Validates redirect targets and URLs to ensure they conform to allowed destinations.

References