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

名称

Use of Non-Canonical URL Paths for Authorization Decisions

描述

The product defines policy namespaces and makes authorization decisions based on the assumption that a URL is canonical. This can allow a non-canonical URL to bypass the authorization.

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: Therefore it is important to specify access control policy that is based on the path information in some canonical form with all alternate encodings rejected (which can be accomplished by a default deny rule).

常见后果

范围：

Access Control

影响：

Bypass Protection Mechanism

注释：

An attacker may be able to bypass the authorization mechanism to gain access to the otherwise-protected URL.

范围：

Confidentiality

影响：

Read Files or Directories

注释：

If a non-canonical URL is used, the server may choose to return the contents of the file, instead of pre-processing the file (e.g. as a program).

相关 CWE

• CWE-180Incorrect Behavior Order: Validate Before Canonicalize
• CWE-863Incorrect AuthorizationHigh