CWE-210

Introduction

CWE-210: Information Exposure Through Self-generated Information occurs when applications inadvertently reveal sensitive data in their own operation-generated output, such as logs, error messages, or transaction histories. When this output includes Personally Identifiable Information (PII), the risks of misuse are significantly heightened. This article discusses the risks associated with PII exposure through CWE-210 and provides remediation techniques, along with coding examples in Java, JavaScript, and Python.

Understanding the Risks

Direct Risks

1. Identity Theft: Exposure of personal identifiers can lead directly to identity theft.
2. Fraud: Exposed financial information, like credit card numbers or account details, can lead to fraudulent transactions.
3. Unauthorized Access: Sensitive information such as passwords or security answers can be used to gain unauthorized access to systems.

Indirect Risks

1. Reputational Damage: Incidents of PII exposure can harm the organization's reputation, potentially leading to customer loss.
2. Regulatory Penalties: Non-compliance with data protection laws (GDPR, HIPAA, etc.) can result in significant fines.
3. Operational Distractions: Managing the fallout from a data breach can consume significant time and resources.

Remediation Techniques

Mitigating the risk of PII exposure in self-generated information involves careful management of what data is included in output streams. Techniques include omitting unnecessary data, masking sensitive details, and encrypting outputs to secure potentially sensitive information.

1. Omitting Data

Avoid logging sensitive data unless absolutely necessary.

public class LogUtility {

    public void logMessage(String message) {

        // Ensure that no sensitive PII is logged

        System.out.println("Log: " + message);

    }

}

2. Masking Data

If data must be included in logs or other outputs, ensure it is sufficiently masked.

public class User {

    public String maskEmail(String email) {

        int atIndex = email.indexOf("@");

        return email.substring(0, 1) + "****" + email.substring(atIndex - 1);

    }

}

3. Encrypting Data

When storing or transmitting data that could be logged or intercepted, use encryption.

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

​

public class EncryptionUtility {

    public static String encrypt(String data) throws Exception {

        KeyGenerator keyGen = KeyGenerator.getInstance("AES");

        keyGen.init(256);

        SecretKey secretKey = keyGen.generateKey();

        Cipher cipher = Cipher.getInstance("AES");

        cipher.init(Cipher.ENCRYPT_MODE, secretKey);

        byte[] encrypted = cipher.doFinal(data.getBytes());

        return java.util.Base64.getEncoder().encodeToString(encrypted);

    }

}

Conclusion

To effectively manage CWE-210 risks, developers and system administrators must be vigilant in controlling the content of output generated by applications, especially when handling PII. Implementing practices such as omitting, masking, and encrypting sensitive data can greatly reduce the likelihood of inadvertent exposure. This ensures compliance with privacy laws and helps maintain trust and security.