diff --git a/services/core/java/com/android/server/biometrics/AuthenticationClient.java b/services/core/java/com/android/server/biometrics/AuthenticationClient.java
index edc8f15a9a03c..8ca37b813b63a 100644
--- a/services/core/java/com/android/server/biometrics/AuthenticationClient.java
+++ b/services/core/java/com/android/server/biometrics/AuthenticationClient.java
@@ -16,16 +16,22 @@
 
 package com.android.server.biometrics;
 
+import android.app.ActivityManager;
+import android.app.ActivityTaskManager;
+import android.content.ComponentName;
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
 import android.hardware.biometrics.BiometricAuthenticator;
 import android.hardware.biometrics.BiometricConstants;
 import android.hardware.biometrics.BiometricsProtoEnums;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.security.KeyStore;
+import android.util.EventLog;
 import android.util.Slog;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /**
  * A class to keep track of the authentication state for a given client.
@@ -148,7 +154,54 @@ public abstract class AuthenticationClient extends ClientMonitor {
                     + ", requireConfirmation: " + mRequireConfirmation
                     + ", user: " + getTargetUserId());
 
+            // Ensure authentication only succeeds if the client activity is on top or is keyguard.
+            boolean isBackgroundAuth = false;
+            if (authenticated && !Utils.isKeyguard(getContext(), getOwnerString())) {
+                try {
+                    final List<ActivityManager.RunningTaskInfo> tasks =
+                            ActivityTaskManager.getService().getTasks(1);
+                    if (tasks == null || tasks.isEmpty()) {
+                        Slog.e(TAG, "No running tasks reported");
+                        isBackgroundAuth = true;
+                    } else {
+                        final ComponentName topActivity = tasks.get(0).topActivity;
+                        if (topActivity == null) {
+                            Slog.e(TAG, "Unable to get top activity");
+                            isBackgroundAuth = true;
+                        } else {
+                            final String topPackage = topActivity.getPackageName();
+                            if (!topPackage.contentEquals(getOwnerString())) {
+                                Slog.e(TAG, "Background authentication detected, top: " + topPackage
+                                        + ", client: " + this);
+                                isBackgroundAuth = true;
+                            }
+                        }
+                    }
+                } catch (RemoteException e) {
+                    Slog.e(TAG, "Unable to get running tasks", e);
+                    isBackgroundAuth = true;
+                }
+            }
+
+            // Fail authentication if we can't confirm the client activity is on top.
+            if (isBackgroundAuth) {
+                Slog.e(TAG, "Failing possible background authentication");
+                authenticated = false;
+
+                // SafetyNet logging for exploitation attempts of b/159249069.
+                final ApplicationInfo appInfo = getContext().getApplicationInfo();
+                EventLog.writeEvent(0x534e4554, "159249069", appInfo != null ? appInfo.uid : -1,
+                        "Attempted background authentication");
+            }
+
             if (authenticated) {
+                // SafetyNet logging for b/159249069 if constraint is violated.
+                if (isBackgroundAuth) {
+                    final ApplicationInfo appInfo = getContext().getApplicationInfo();
+                    EventLog.writeEvent(0x534e4554, "159249069", appInfo != null ? appInfo.uid : -1,
+                            "Successful background authentication!");
+                }
+
                 mAlreadyDone = true;
 
                 if (listener != null) {