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Insufficient Control of Resource Identifiers (aka 'Resource Injection') Status: Draft Weakness ID: 99 (Weakness Base)Description Summary The software allows user-controlled input to control resource identifiers. This may enable an attacker to access or modify otherwise protected system resources. Likelihood of Exploit High Weakness Ordinalities Primary (where the weakness exists independent of other weaknesses) Causal Nature Explicit (an explicit
weakness resulting from behavior of the developer) Potential Mitigations Assume all input is malicious. Use an appropriate combination of black lists and white lists to ensure only valid and expected input is processed by the system. Demonstrative Examples Example 1: 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. Java Example: String rName = request.getParameter("reportName"); File rFile = new File("/usr/local/apfr/reports/" + rName); ... rFile.delete();
Example 2: 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. C++ Example: ifstream ifs(argv[0]); string s; ifs >> s; cout << s;
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. Other Notes A resource injection issue occurs when the following two conditions are met: 1. 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. 2. 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. Note: Resource injection that involves resources stored on the filesystem goes by the name path manipulation and is reported in separate category. See the path manipulation description for further details of this vulnerability. Relationships
Taxonomy Mappings
Applicable Platforms Languages All Time of Introduction  Architecture and Design ImplementationRelated Attack Patterns
White Box Definitions A weakness where the code path has: 1. start statement that accepts input followed by 2. a statement that allocates a System Resource where the input is part of the name of the System Resource 3. end statement that accesses the System Resource where the input is undesirable Where "input is undesirable" is defined through the following scenarios: 1. input not validated 2. input incorrectly validated Content History Submissions 7 Pernicious Kingdoms. (Externally Mined) Modifications Eric Dalci. Cigital. 2008-07-01. (External) updated Time_of_Introduction KDM Analytics. 2008-08-01. (External) added/updated white box definitions CWE Content Team. MITRE. 2008-09-08. (Internal) updated Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities Previous Entry Names Resource Injection (changed 2008-04-11) |
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