Id	SetWorldReadable
Summary	File.setReadable() used to make file world-readable
Severity	Warning
Category	Security
Platform	Android
Vendor	Android Open Source Project
Feedback	https://issuetracker.google.com/issues/new?component=192708
Since	1.5.0 (November 2015)
Affects	Kotlin and Java files
Editing	This check runs on the fly in the IDE editor
See	https://goo.gle/SetWorldReadable
Implementation	Source Code
Tests	Source Code

Here is an example of lint warnings produced by this check:

src/test/pkg/WorldWriteableFile.java:41:Warning: Setting file
permissions to world-readable can be risky, review carefully
[SetWorldReadable]
    mFile.setReadable(true, false);
    ------------------------------

Here is the source file referenced above:

src/test/pkg/WorldWriteableFile.java:

package test.pkg;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.InputStream;
import java.io.FileNotFoundException;
import android.content.Context;
import android.content.SharedPreferences;
import android.app.Activity;
import android.os.Bundle;

public class WorldWriteableFile extends Activity {
    File mFile;
    Context mContext;

    public void foo() {
        OutputStream out = null;
        SharedPreferences prefs = null;
        File dir = null;

        boolean success = false;
        try {
            //out = openFileOutput(mFile.getName()); // ok
            out = openFileOutput(mFile.getName(), MODE_PRIVATE); // ok
            out = openFileOutput(mFile.getName(), MODE_WORLD_WRITEABLE);
            out = openFileOutput(mFile.getName(), MODE_WORLD_READABLE);

            prefs = getSharedPreferences(mFile.getName(), 0); // ok
            prefs = getSharedPreferences(mFile.getName(), MODE_PRIVATE); // ok
            prefs = getSharedPreferences(mFile.getName(), MODE_WORLD_WRITEABLE);
            prefs = getSharedPreferences(mFile.getName(), MODE_WORLD_READABLE);

            dir = getDir(mFile.getName(), MODE_PRIVATE); // ok
            dir = getDir(mFile.getName(), MODE_WORLD_WRITEABLE);
            dir = getDir(mFile.getName(), MODE_WORLD_READABLE);

            mFile.setReadable(true, true); // ok
            mFile.setReadable(false, true); // ok
            mFile.setReadable(false, false); // ok
            mFile.setReadable(true, false);
            mFile.setReadable(true); // ok
            mFile.setReadable(false); // ok

            mFile.setWritable(true, true); // ok
            mFile.setWritable(false, true); // ok
            mFile.setWritable(false, false); // ok
            mFile.setWritable(true, false);
            mFile.setWritable(true); // ok
            mFile.setWritable(false); // ok

            // Flickr.get().downloadPhoto(params[0], Flickr.PhotoSize.LARGE,
            // out);
            success = true;
        } catch (FileNotFoundException e) {
        }
    }
}

You can also visit the source code for the unit tests for this check to see additional scenarios.

The above example was automatically extracted from the first unit test found for this lint check, SecurityDetector.testWorldWriteable. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=192708.

You can suppress false positives using one of the following mechanisms:

• Using a suppression annotation like this on the enclosing element:

  // Kotlin
  @Suppress("SetWorldReadable")
  fun method() {
     openFileOutput(...)
  }

  or

  // Java
  @SuppressWarnings("SetWorldReadable")
  void method() {
     openFileOutput(...);
  }

• Using a suppression comment like this on the line above:

  //noinspection SetWorldReadable
  problematicStatement()

• Using a special lint.xml file in the source tree which turns off the check in that folder and any sub folder. A simple file might look like this:

  <?xml version="1.0" encoding="UTF-8"?>
  <lint>
      <issue id="SetWorldReadable" severity="ignore" />
  </lint>

  Instead of ignore you can also change the severity here, for example from error to warning. You can find additional documentation on how to filter issues by path, regular expression and so on here.

• In Gradle projects, using the DSL syntax to configure lint. For example, you can use something like

  lintOptions {
      disable 'SetWorldReadable'
  }

  In Android projects this should be nested inside an android { } block.

• For manual invocations of lint, using the --ignore flag:

  $ lint --ignore SetWorldReadable ...`

• Last, but not least, using baselines, as discussed here.