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Weakness (CWE)

CWE-647: Use of Non-Canonical URL Paths for Authorization Decisions

Variant Incomplete

The product defines policy namespaces and makes authorization decisions based on the assumption that a URL is canonical.

More detail

If an application defines policy namespaces and makes authorization decisions based on the URL, but it does not require or convert to a canonical URL before making the authorization decision, then it opens the application to attack. For example, if the application only wants to allow access to http://www.example.com/mypage, then the attacker might be able to bypass this restriction using equivalent URLs such as:

- http://WWW.EXAMPLE.COM/mypage

- http://www.example.com/%6Dypage (alternate encoding)

- http://192.168.1.1/mypage (IP address)

- http://www.example.com/mypage/ (trailing /)

- http://www.example.com:80/mypage

How to prevent it (1 mitigation)

  1. Architecture and Design

    Make access control policy based on path information in canonical form, with all alternate encodings rejected (which can be accomplished by a default deny rule). Consider very restrictive regular expressions to validate that the path is in the expected form. Reject all alternate path encodings that are not in the expected canonical form.

Source: MITRE CWE-647

All Critical High Medium Low Exploited only Public exploit

1 result · Clear filters · Feed

  • High 8.6
    CVE-2022-43939 Exploited Public exploit EPSS 92%

    Hitachi Vantara Pentaho Business Analytics Server - Use of Non-Canonical URL Paths for Authorization Decisions

    Hitachi Vantara Pentaho Business Analytics Server versions before 9.4.0.1 and 9.3.0.2, including 8.3.x contain security restrictions using non-canonical URLs which can be circumvented.

    Hitachi Vantara Pentaho Business Analytics Server
    KEV Mar 3, 2025