CWE-1341: Multiple Releases of Same Resource or Handle

What is Multiple Releases of Same Resource or Handle?

• Overview: Multiple Releases of Same Resource or Handle occurs when a program attempts to close or release a resource more than once without reopening it. This can lead to undefined behavior, as the system might not expect the resource to be released multiple times.

• Exploitation Methods:

• Attackers can exploit this vulnerability by inducing conditions where resources are released multiple times, potentially leading to instability or crashes.
• Common attack patterns involve manipulating program state or input to force incorrect resource management, such as double-free vulnerabilities in memory management.

• Security Impact:

• Direct consequences include memory corruption, data corruption, and crashes.
• Potential cascading effects include execution path corruption and security bypasses.
• Business impact may involve system downtime, data loss, and increased maintenance costs.

• Prevention Guidelines:

• Specific code-level fixes include implementing checks to ensure resources are only released once.
• Security best practices involve using resource management patterns like RAII (Resource Acquisition Is Initialization) in C++ or try-with-resources in Java.
• Recommended tools and frameworks include static analysis tools to detect improper resource handling and using language-specific features that prevent manual resource management errors.

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Technical Details

Likelihood of Exploit: Not specified

Affected Languages: Java, Rust, Not Language-Specific, C, C++

Affected Technologies: Not Technology-Specific

Vulnerable Code Example

import java.io.FileInputStream;
import java.io.IOException;

public class ResourceHandler {
    public void readFile(String fileName) {
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream(fileName);
            // Read file contents
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (fileInputStream != null) {
                    fileInputStream.close(); // First close
                }
                if (fileInputStream != null) {
                    fileInputStream.close(); // Second close - Vulnerability!
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}

Explanation:

• Lines {10-13}: In the finally block, fileInputStream is checked and closed twice. The second call to close() is redundant and can cause exceptions or undefined behavior if the resource is accessed after being closed. This demonstrates the CWE-1341 vulnerability of multiple releases of the same resource.

How to fix Multiple Releases of Same Resource or Handle?

To fix this vulnerability, ensure each resource is closed exactly once. This can be achieved by:

1. Removing redundant close calls: Ensure the close() method is called only once.
2. Using try-with-resources: In Java 7 and above, the try-with-resources statement can automatically manage the resource, ensuring it's closed properly without needing a finally block.

Fixed Code Example

import java.io.FileInputStream;
import java.io.IOException;

public class ResourceHandler {
    public void readFile(String fileName) {
        // Use try-with-resources for automatic resource management
        try (FileInputStream fileInputStream = new FileInputStream(fileName)) {
            // Read file contents
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Explanation:

• Lines {8-10}: The try-with-resources statement is used, which ensures that fileInputStream is closed automatically when the try block exits. This pattern eliminates the risk of multiple resource releases, simplifies the code, and enhances safety by ensuring that resources are managed correctly.