Prevent Intent Redirection Vulnerabilities

Why this matters

Intent redirection occurs when an app exposes an intent-processing component that can be manipulated by malicious applications, leading to security risks.

Bad vs. good

Side-by-side examples engineers can pattern-match during review.

Avoid

public class Noncompliant extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");
        startActivity(forward); // Noncompliant
    }
}

Prefer

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");

        ComponentName title = forward.resolveActivity(getPackageManager());
        if (title.getPackageName().equals("safePackage") &&
                title.getClassName().equals("safeClass")) {
            startActivity(forward);
        }
    }
}

More snippets

Bad

public class Noncompliant extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");
        startActivity(forward); // Noncompliant
    }
}

Good

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");

        ComponentName title = forward.resolveActivity(getPackageManager());
        if (title.getPackageName().equals("safePackage") &&
                title.getClassName().equals("safeClass")) {
            startActivity(forward);
        }
    }
}

Related rules

From the same buckets as this rule.

Critical

Always sanitize user inputs

Check if user inputs are sanitized before being used in rendering or database queries. Unsanitized inputs can lead to injection vulnerabilities like XSS or SQL injection.

security-hardening

Critical

Always Verify Server Certificates in SSL/TLS Connections

Ensure that SSL/TLS certificate validation is always enabled to prevent Man-in-the-Middle (MitM) attacks.

security-hardening

Critical

Avoid modifying built-in prototypes

Detect modifications to built-in prototypes. Modifying built-in objects can lead to compatibility issues and unexpected behavior. Recommend creating helper functions instead.

maintainabilitysecurity-hardening

Bad vs. good

Side-by-side examples engineers can pattern-match during review.

Avoid

public class Noncompliant extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");
        startActivity(forward); // Noncompliant
    }
}

Prefer

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");

        ComponentName title = forward.resolveActivity(getPackageManager());
        if (title.getPackageName().equals("safePackage") &&
                title.getClassName().equals("safeClass")) {
            startActivity(forward);
        }
    }
}

More snippets

Bad

public class Noncompliant extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");
        startActivity(forward); // Noncompliant
    }
}

Good

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Intent intent = getIntent();
        Intent forward = (Intent) intent.getParcelableExtra("anotherintent");

        ComponentName title = forward.resolveActivity(getPackageManager());
        if (title.getPackageName().equals("safePackage") &&
                title.getClassName().equals("safeClass")) {
            startActivity(forward);
        }
    }
}

Related rules

From the same buckets as this rule.

Critical

Always sanitize user inputs

Check if user inputs are sanitized before being used in rendering or database queries. Unsanitized inputs can lead to injection vulnerabilities like XSS or SQL injection.

security-hardening

Critical

Always Verify Server Certificates in SSL/TLS Connections

Ensure that SSL/TLS certificate validation is always enabled to prevent Man-in-the-Middle (MitM) attacks.

security-hardening

Critical

Avoid modifying built-in prototypes

Detect modifications to built-in prototypes. Modifying built-in objects can lead to compatibility issues and unexpected behavior. Recommend creating helper functions instead.

maintainabilitysecurity-hardening