JAVA.IO.TAINT.REGEX : Tainted Regular Expression (Java)

Summary

Tainted data flows into a field annotated as @RegexTrusted, or into a regular expression.

Checks for this class use the CodeSonar Java taint analysis. See Taint Tracking for CodeSonar Java Warning Classes for more information on this analysis, including lists of the methods that CodeSonar automatically recognizes as relevant and information about specifying additional methods that CodeSonar should recognize as taint sources, sinks, or sanitizers.

Use configuration parameter JAVA_ANALYSIS_ADVANCED_INJECTION to specify the level of checking to perform for this and other taint-related warning classes:

• For basic checking, set JAVA_ANALYSIS_ADVANCED_INJECTION=No in your project configuration file.
• For advanced checking, set JAVA_ANALYSIS_ADVANCED_INJECTION=Yes.

Properties

WARNING_FILTER += discard class="Tainted Regular Expression (Java)"

Example

import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RegexInjectionExample {

    String adminUserName;
    
    public void processRequest(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String user = request.getParameter("userName");
        String data = request.getParameter("data");
        if(adminUserName.matches(user)){    // "Tainted Regular Expression (Java)" warning issued here.  
           // ...
        }
    }
    // ...
}

In this example, the programmer should avoid a direct flow of untrusted input into a regular expression. This is very dangerous because could lead to infinite recursions or untrusted behaviors (steal sensitive data, perform a privilege escalation, etc.). The solution is to use a regex escape method that guarantees the correct handling of input, so that it becomes harmless (see the list of Java methods recognized by CodeSonar), or to implement proprietary sanitizing methods.

Resolution

Verify that a security error actually corresponds to unconstrained information flow from source locations into sink locations. If this is the case, add a sanitizing algorithm to clean data before it flows into sinks, or use safe statements to propagate data inside the program.

Relevant Configuration File Parameters

The following configuration file parameters affect checks for this warning class.

• JAVA_ANALYSIS_ADVANCED_INJECTION
• JAVA_ANALYSIS_FIELD_SENSITIVE
• JAVA_ANALYSIS_MERGE_CREATION_POINTS
• JAVA_ANALYSIS_TRUST_DATABASE
• JAVA_ANALYSIS_TRUST_DEVICE
• JAVA_ANALYSIS_TRUST_ENVIRONMENT
• JAVA_ANALYSIS_TRUST_EXTERNAL_STREAMS
• JAVA_ANALYSIS_TRUST_USER_INPUT
• REPORT_SIMILAR_WARNINGS
• WARNING_FILTER