1427
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
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).
Relationships
The table(s) below shows the weaknesses and high level categories that are related to this
weakness. These relationships are defined as ChildOf, ParentOf, MemberOr and give insight to
similar items that may exist at higher and lower levels of abstraction. In addition, relationships such
as PeerOf and CanAlsoBe are defined to show similar weaknesses that may want to be explored.
Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name Page
ChildOf 863 Incorrect Authorization 1787
Relevant to the view "Architectural Concepts" (CWE-1008)
Nature Type ID Name Page
MemberOf 1011 Authorize Actors 2425
Applicable Platforms
Language : Not Language-Specific (Prevalence = Undetermined)
Technology : Web Server (Prevalence = Undetermined)
Likelihood Of Exploit
High
Common Consequences
Scope Impact Likelihood
Access Control Bypass Protection Mechanism
An attacker may be able to bypass the authorization
mechanism to gain access to the otherwise-protected URL.
Confidentiality Read Files or Directories
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).
Detection Methods
Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST),
can find some instances of this weakness by analyzing source code (or binary/compiled code)
without having to execute it. Typically, this is done by building a model of data flow and control
flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input)
with "sinks" (destinations where the data interacts with external components, a lower layer such
as the OS, etc.)
Effectiveness = High
CWE Version 4.14
CWE-648: Incorrect Use of Privileged APIs
CWE-648: Incorrect Use of Privileged APIs