CWE-99: Improper Control of Resource Identifiers ('Resource Injection')

Description:
The product receives input from an upstream component, but it does not restrict or incorrectly restricts the input before it is used as an identifier for a resource that may be outside the intended sphere of control.

Extended Description:
A resource injection issue occurs when the following two conditions are met: 
                
                   An attacker can specify the identifier used to access a system resource. For example, an attacker might be able to specify part of the name of a file to be opened or a port number to be used. 
                   By specifying the resource, the attacker gains a capability that would not otherwise be permitted. For example, the program may give the attacker the ability to overwrite the specified file, run with a configuration controlled by the attacker, or transmit sensitive information to a third-party server. 
                
             This may enable an attacker to access or modify otherwise protected system resources.

Affected languages: Not Language-Specific
Parent weaknesses: CWE-74

Consequences:
  - Confidentiality: Read Application Data

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 havin

Mitigations:
  - [Implementation] Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. 
                   When pe

Demonstrative examples:
The following Java code uses input from an HTTP request to create a file name. The programmer has not considered the possibility that an attacker could provide a file name such as "../../tomcat/conf/server.xml", which causes the application to delete one of its own configuration files.

String rName = request.getParameter("reportName"); File rFile = new File("/usr/local/apfr/reports/" + rName); ... rFile.delete();

The following code uses input from the command line to determine which file to open and echo back to the user. If the program runs with privileges and malicious users can create soft links to the file, they can use the program to read the first part of any file on the system.
The kind of resource the data affects indicates the kind of content that may be dangerous. For example, data containing special characters like period, slash, and backslash, are risky when used in methods that interact with the file system. (Resource injection, when it is related to file system resources, sometimes goes by the name "path manipulation.") Similarly, data that contains URLs and URIs is risky for functions that create remote connections.
ifstream ifs(argv[0]); string s; ifs >> s; cout << s;

Real-world examples:
  - CVE-2013-4787: chain: mobile OS verifies cryptographic signature of file in an archive, but then installs a different file with the same name that is also listed in the archive.