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fix(share): Add nonce validation to broadcast receiver on Android #2592

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fix(share): Add nonce validation to broadcast receiver on Android #2592

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faeabc7
fix(share): Add nonce validation to prevent receiver spoofing
OS-pedrogustavobilro Sep 7, 2026
1a1d027
chore: correct code comments
OS-pedrogustavobilro Sep 7, 2026
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33 changes: 30 additions & 3 deletions share/android/src/main/java/com/capacitorjs/plugins/share/SharePlugin.java
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Original file line number Diff line number Diff line change
Expand Up @@ -19,25 +19,44 @@
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import org.json.JSONException;

@CapacitorPlugin(name = "Share")
public class SharePlugin extends Plugin {

private static final String NONCE_EXTRA_KEY = "_share_nonce";

private BroadcastReceiver broadcastReceiver;
private boolean stopped = false;
private boolean isPresenting = false;
private ComponentName chosenComponent;
private String expectedNonce;

@Override
public void load() {
broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// Validate nonce to prevent spoofing from other apps
// Reference: https://github.com/ionic-team/capacitor-plugins/pull/2592
String receivedNonce = intent.getStringExtra(NONCE_EXTRA_KEY);
if (receivedNonce == null || !receivedNonce.equals(expectedNonce)) {
// Reject broadcasts that don't have the correct nonce
return;
}

ComponentName component;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
chosenComponent = intent.getParcelableExtra(Intent.EXTRA_CHOSEN_COMPONENT, ComponentName.class);
component = intent.getParcelableExtra(Intent.EXTRA_CHOSEN_COMPONENT, ComponentName.class);
} else {
chosenComponent = getParcelableExtraLegacy(intent, Intent.EXTRA_CHOSEN_COMPONENT);
component = getParcelableExtraLegacy(intent, Intent.EXTRA_CHOSEN_COMPONENT);
}

// Only clear nonce if we successfully got the component data
if (component != null) {
chosenComponent = component;
expectedNonce = null;
}
}
};
Expand All @@ -64,6 +83,7 @@ private void activityResult(PluginCall call, ActivityResult result) {
call.resolve(callResult);
}
isPresenting = false;
expectedNonce = null;
}

@PluginMethod
Expand Down Expand Up @@ -117,6 +137,12 @@ public void share(PluginCall call) {
if (files != null && files.length() != 0) {
shareFiles(files, intent, call);
}

// Generate a random nonce to prevent spoofing via exported receiver
expectedNonce = UUID.randomUUID().toString();
Intent callbackIntent = new Intent(Intent.EXTRA_CHOSEN_COMPONENT);
callbackIntent.putExtra(NONCE_EXTRA_KEY, expectedNonce);

int flags = PendingIntent.FLAG_UPDATE_CURRENT;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
flags = flags | PendingIntent.FLAG_MUTABLE;
Expand All @@ -126,7 +152,7 @@ public void share(PluginCall call) {
}

// requestCode parameter is not used. Providing 0
PendingIntent pi = PendingIntent.getBroadcast(getContext(), 0, new Intent(Intent.EXTRA_CHOSEN_COMPONENT), flags);
PendingIntent pi = PendingIntent.getBroadcast(getContext(), 0, callbackIntent, flags);
Intent chooser = Intent.createChooser(intent, dialogTitle, pi.getIntentSender());
chosenComponent = null;
chooser.addCategory(Intent.CATEGORY_DEFAULT);
Expand Down Expand Up @@ -180,6 +206,7 @@ private void shareFiles(JSArray files, Intent intent, PluginCall call) {

@Override
protected void handleOnDestroy() {
expectedNonce = null;
if (broadcastReceiver != null) {
getActivity().unregisterReceiver(broadcastReceiver);
}
Expand Down
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