Mejoras de seguridad

Android mejora continuamente sus capacidades y ofertas de seguridad. Vea las listas de mejoras por lanzamiento en la navegación izquierda.

Androide 14

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 14:

  • Hardware-assisted AddressSanitizer (HWASan), introduced in Android 10, is a memory error detection tool similar to AddressSanitizer. Android 14 brings significant improvements to HWASan. Learn how it helps prevent bugs from making it into Android releases, HWAddressSanitizer
  • In Android 14, starting with apps that share location data with third-parties, the system runtime permission dialog now includes a clickable section that highlights the app's data-sharing practices, including information such as why an app may decide to share data with third parties.
  • Android 12 introduced an option to disable 2G support at the modem level, which protects users from the inherent security risk from 2G's obsolete security model. Recognizing how critical disabling 2G could be for enterprise customers, Android 14 enables this security feature in Android Enterprise, introducing support for IT admins to restrict the ability of a managed device to downgrade to 2G connectivity.
  • Added support to reject null-ciphered cellular connections, ensuring that circuit-switched voice and SMS traffic is always encrypted and protected from passive over-the-air interception. Learn more about Android's program to harden cellular connectivity.
  • Added support for multiple IMEIs
  • Since Android 14, AES-HCTR2 is the preferred mode of filenames encryption for devices with accelerated cryptography instructions.
  • Cellular connectivity
  • Documentation added for Android Safety Center
  • If your app targets Android 14 and uses Dynamic Code Loading (DCL), all dynamically-loaded files must be marked as read-only. Otherwise, the system throws an exception. We recommend that apps avoid dynamically loading code whenever possible, as doing so greatly increases the risk that an app can be compromised by code injection or code tampering.

Check out our full AOSP release notes and the Android Developer features and changes list.

androide 13

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 13:

  • Android 13 adds multi-document presentation support. This new Presentation Session interface enables an application to do a multi-document presentation, something which isn't possible with the existing API. For further information, refer to Identity Credential
  • In Android 13, intents originating from external apps are delivered to an exported component if and only if the intents match their declared intent-filter elements.
  • Open Mobile API (OMAPI) is a standard API used to communicate with a device's Secure Element. Before Android 13, only applications and framework modules had access to this interface. By converting it to a vendor stable interface, HAL modules are also capable of communicating with the secure elements through the OMAPI service. For more information, see OMAPI Vendor Stable Interface.
  • As of Android 13-QPR, shared UIDs are deprecated. Users of Android 13 or higher should put the line `android:sharedUserMaxSdkVersion="32"` in their manifest. This entry prevents new users from getting a shared UID. For further information on UIDs, see Application signing.
  • Android 13 added support Keystore symmetric cryptographic primitives such as AES (Advanced Encryption Standard), HMAC (Keyed-Hash Message Authentication Code), and asymmetric cryptographic algorithms (including Elliptic Curve, RSA2048, RSA4096, and Curve 25519)
  • Android 13 (API level 33) and higher supports a runtime permission for sending non-exempt notifications from an app. This gives users control over which permission notifications they see.
  • Added per-use prompt for apps requesting access to all device logs, giving users the ability to allow or deny access.
  • introduced the Android Virtualization Framework (AVF), which brings together different hypervisors under one framework with standardized APIs. It provides secure and private execution environments for executing workloads isolated by hypervisor.
  • Introduced APK signature scheme v3.1 All new key rotations that use apksigner will use the v3.1 signature scheme by default to target rotation for Android 13 and higher.

Check out our full AOSP release notes and the Android Developer features and changes list.

androide 12

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 12:

  • Android 12 introduces the BiometricManager.Strings API, which provides localized strings for apps that use BiometricPrompt for authentication. These strings are intended to be device-aware and provide more specificity about which authentication type(s) may be used. Android 12 also includes support for under-display fingerprint sensors
  • Support added for under-display fingerprint sensors
  • Introduction of the Fingerprint Android Interface Definition Language (AIDL)
  • Support for new Face AIDL
  • Introduction of Rust as a language for platform development
  • The option for users to grant access only to their approximate location added
  • Added Privacy indicators on the status bar when an app is using the camera or microphone
  • Android's Private Compute Core (PCC)
  • Added an option to disable 2G support

androide 11

Every Android release includes dozens of security enhancements to protect users. For a list of some of the major security enhancements available in Android 11, see the Android Release Notes.

androide 10

Cada versión de Android incluye docenas de mejoras de seguridad para proteger a los usuarios. Android 10 incluye varias mejoras de seguridad y privacidad. Consulte las notas de la versión de Android 10 para obtener una lista completa de los cambios en Android 10.

Seguridad

LímitesDesinfectante

Android 10 implementa BoundsSanitizer (BoundSan) en Bluetooth y códecs. BoundSan utiliza el desinfectante de límites de UBSan. Esta mitigación se habilita a nivel de módulo. Ayuda a mantener seguros los componentes críticos de Android y no debe desactivarse. BoundSan está habilitado en los siguientes códecs:

  • libFLAC
  • libavcdec
  • libavcenc
  • libhevcdec
  • libmpeg2
  • libopus
  • libvpx
  • libspeexresampler
  • libvorbisidec
  • libaac
  • libxaac

Memoria de solo ejecución

De forma predeterminada, las secciones de código ejecutable para los binarios del sistema AArch64 están marcadas como de solo ejecución (no legibles) como una mitigación de refuerzo contra ataques de reutilización de código justo a tiempo. El código que mezcla datos y código y el código que inspecciona intencionadamente estas secciones (sin reasignar primero los segmentos de memoria como legibles) ya no funciona. Las aplicaciones con un SDK de destino de Android 10 (nivel de API 29 o superior) se ven afectadas si la aplicación intenta leer secciones de código de bibliotecas del sistema habilitadas para memoria de solo ejecución (XOM) en la memoria sin marcar primero la sección como legible.

Acceso ampliado

Los agentes de confianza, el mecanismo subyacente utilizado por los mecanismos de autenticación terciarios como Smart Lock, solo pueden extender el desbloqueo en Android 10. Los agentes de confianza ya no pueden desbloquear un dispositivo bloqueado y solo pueden mantenerlo desbloqueado durante un máximo de cuatro horas.

Autenticación facial

La autenticación facial permite a los usuarios desbloquear su dispositivo simplemente mirando la parte frontal de su dispositivo. Android 10 agrega soporte para una nueva pila de autenticación facial que puede procesar de forma segura los fotogramas de la cámara, preservando la seguridad y la privacidad durante la autenticación facial en hardware compatible. Android 10 también proporciona una manera fácil para que las implementaciones compatibles con la seguridad permitan la integración de aplicaciones para transacciones como banca en línea u otros servicios.

Desinfección de desbordamiento de enteros

Android 10 habilita la desinfección de desbordamiento de enteros (IntSan) en códecs de software. Asegúrese de que el rendimiento de reproducción sea aceptable para cualquier códec que no sea compatible con el hardware del dispositivo. IntSan está habilitado en los siguientes códecs:

  • libFLAC
  • libavcdec
  • libavcenc
  • libhevcdec
  • libmpeg2
  • libopus
  • libvpx
  • libspeexresampler
  • libvorbisidec

Componentes del sistema modular

Android 10 modulariza algunos componentes del sistema Android y permite actualizarlos fuera del ciclo de lanzamiento normal de Android. Algunos módulos incluyen:

OEMCrypto

Android 10 usa OEMCrypto API versión 15.

escudo

Scudo es un asignador de memoria dinámico en modo de usuario diseñado para ser más resistente contra vulnerabilidades relacionadas con el montón. Proporciona las primitivas de asignación y desasignación de C estándar, así como las primitivas de C++.

Pila de llamadas de sombra

ShadowCallStack (SCS) es un modo de instrumentación de LLVM que protege contra sobrescrituras de direcciones de retorno (como desbordamientos del búfer de pila) al guardar la dirección de retorno de una función en una instancia de ShadowCallStack asignada por separado en el prólogo de funciones de funciones que no son hojas y cargar la dirección de retorno desde la instancia ShadowCallStack en el epílogo de la función.

WPA3 y Wi-Fi mejorado abierto

Android 10 agrega soporte para los estándares de seguridad Wi-Fi Protected Access 3 (WPA3) y Wi-Fi Enhanced Open para brindar mayor privacidad y solidez contra ataques conocidos.

Privacidad

Acceso a la aplicación cuando se apunta a Android 9 o inferior

Si su aplicación se ejecuta en Android 10 o superior pero apunta a Android 9 (nivel de API 28) o inferior, la plataforma aplica el siguiente comportamiento:

  • Si su aplicación declara un elemento <uses-permission> para ACCESS_FINE_LOCATION o ACCESS_COARSE_LOCATION , el sistema agrega automáticamente un elemento <uses-permission> para ACCESS_BACKGROUND_LOCATION durante la instalación.
  • Si su aplicación solicita ACCESS_FINE_LOCATION o ACCESS_COARSE_LOCATION , el sistema agrega automáticamente ACCESS_BACKGROUND_LOCATION a la solicitud.

Restricciones de actividad en segundo plano

A partir de Android 10, el sistema impone restricciones al iniciar actividades desde segundo plano . Este cambio de comportamiento ayuda a minimizar las interrupciones para el usuario y le mantiene más control de lo que se muestra en su pantalla. Siempre que su aplicación inicie actividades como resultado directo de la interacción del usuario, lo más probable es que no se vea afectada por estas restricciones.
Para obtener más información sobre la alternativa recomendada para iniciar actividades desde segundo plano, consulte la guía sobre cómo alertar a los usuarios sobre eventos urgentes en su aplicación.

Metadatos de la cámara

Android 10 cambia la amplitud de información que el método getCameraCharacteristics() devuelve de forma predeterminada. En particular, su aplicación debe tener el permiso CAMERA para poder acceder a metadatos potencialmente específicos del dispositivo que se incluyen en el valor de retorno de este método.
Para obtener más información sobre estos cambios, consulte la sección sobre campos de cámara que requieren permiso .

Datos del portapapeles

A menos que su aplicación sea el editor de métodos de entrada (IME) predeterminado o sea la aplicación que actualmente tiene el foco, su aplicación no puede acceder a los datos del portapapeles en Android 10 o superior.

Ubicación del dispositivo

Para admitir el control adicional que los usuarios tienen sobre el acceso de una aplicación a la información de ubicación, Android 10 introduce el permiso ACCESS_BACKGROUND_LOCATION .
A diferencia de los permisos ACCESS_FINE_LOCATION y ACCESS_COARSE_LOCATION , el permiso ACCESS_BACKGROUND_LOCATION solo afecta el acceso de una aplicación a la ubicación cuando se ejecuta en segundo plano. Se considera que una aplicación accede a la ubicación en segundo plano a menos que se cumpla una de las siguientes condiciones:

  • Se ve una actividad perteneciente a la aplicación.
  • La aplicación ejecuta un servicio en primer plano que ha declarado untipo de location de servicio en primer plano.
    Para declarar el tipo de servicio en primer plano para un servicio en su aplicación, configure targetSdkVersion o compileSdkVersion de su aplicación en 29 o superior. Obtenga más información sobre cómo los servicios en primer plano pueden continuar con las acciones iniciadas por el usuario que requieren acceso a la ubicación.

Almacenamiento externo

De forma predeterminada, las aplicaciones orientadas a Android 10 y versiones posteriores reciben acceso limitado al almacenamiento externo o almacenamiento limitado . Estas aplicaciones pueden ver los siguientes tipos de archivos dentro de un dispositivo de almacenamiento externo sin necesidad de solicitar ningún permiso de usuario relacionado con el almacenamiento:

  • Archivos en el directorio específico de la aplicación, a los que se accede mediante getExternalFilesDir() .
  • Fotos, vídeos y clips de audio que la aplicación creó desde la tienda multimedia .

Para obtener más información sobre el almacenamiento con alcance, así como también cómo compartir, acceder y modificar archivos guardados en dispositivos de almacenamiento externos, consulte las guías sobre cómo administrar archivos en almacenamiento externo y acceder y modificar archivos multimedia .

Aleatorización de direcciones MAC

En dispositivos que ejecutan Android 10 o superior, el sistema transmite direcciones MAC aleatorias de forma predeterminada.
Si su aplicación maneja un caso de uso empresarial , la plataforma proporciona API para varias operaciones relacionadas con direcciones MAC:

  • Obtener una dirección MAC aleatoria : las aplicaciones del propietario del dispositivo y las aplicaciones del propietario del perfil pueden recuperar la dirección MAC aleatoria asignada a una red específica llamando a getRandomizedMacAddress() .
  • Obtenga la dirección MAC real de fábrica: las aplicaciones del propietario del dispositivo pueden recuperar la dirección MAC real del hardware de un dispositivo llamando a getWifiMacAddress() . Este método es útil para rastrear flotas de dispositivos.

Identificadores de dispositivos no reiniciables

A partir de Android 10, las aplicaciones deben tener el permiso privilegiado READ_PRIVILEGED_PHONE_STATE para poder acceder a los identificadores no reiniciables del dispositivo, que incluyen tanto IMEI como número de serie.

Si su aplicación no tiene el permiso e intenta solicitar información sobre identificadores que no se pueden restablecer de todos modos, la respuesta de la plataforma varía según la versión del SDK de destino:

  • Si su aplicación tiene como destino Android 10 o superior, se produce una SecurityException .
  • Si su aplicación está destinada a Android 9 (nivel de API 28) o inferior, el método devuelve datos null o de marcador de posición si la aplicación tiene el permiso READ_PHONE_STATE . De lo contrario, se produce una SecurityException .

Reconocimiento de actividad física

Android 10 introduce el permiso de tiempo de ejecución android.permission.ACTIVITY_RECOGNITION para aplicaciones que necesitan detectar el recuento de pasos del usuario o clasificar la actividad física del usuario, como caminar, andar en bicicleta o moverse en un vehículo. Esto está diseñado para brindar a los usuarios visibilidad de cómo se usan los datos del sensor del dispositivo en Configuración.
Algunas bibliotecas dentro de los servicios de Google Play, como la API de reconocimiento de actividad y la API de Google Fit , no proporcionan resultados a menos que el usuario haya otorgado este permiso a su aplicación.
Los únicos sensores integrados en el dispositivo que requieren que usted declare este permiso son los sensores del contador de pasos y del detector de pasos .
Si su aplicación está orientada a Android 9 (nivel de API 28) o inferior, el sistema otorga automáticamente el permiso android.permission.ACTIVITY_RECOGNITION a su aplicación, según sea necesario, si su aplicación cumple cada una de las siguientes condiciones:

  • El archivo de manifiesto incluye el permiso com.google.android.gms.permission.ACTIVITY_RECOGNITION .
  • El archivo de manifiesto no incluye el permiso android.permission.ACTIVITY_RECOGNITION .

Si system-auto otorga el permiso android.permission.ACTIVITY_RECOGNITION , su aplicación conserva el permiso después de actualizarla para apuntar a Android 10. Sin embargo, el usuario puede revocar este permiso en cualquier momento en la configuración del sistema.

Restricciones del sistema de archivos /proc/net

En dispositivos que ejecutan Android 10 o superior, las aplicaciones no pueden acceder /proc/net , que incluye información sobre el estado de la red de un dispositivo. Las aplicaciones que necesitan acceso a esta información, como las VPN, deben usar la clase NetworkStatsManager o ConnectivityManager .

Grupos de permisos eliminados de la interfaz de usuario

A partir de Android 10, las aplicaciones no pueden buscar cómo se agrupan los permisos en la interfaz de usuario.

Eliminación de afinidad de contactos

A partir de Android 10, la plataforma no realiza un seguimiento de la información de afinidad de los contactos. Como resultado, si su aplicación realiza una búsqueda en los contactos del usuario, los resultados no están ordenados por frecuencia de interacción.
La guía sobre ContactsProvider contiene un aviso que describe los campos y métodos específicos que están obsoletos en todos los dispositivos a partir de Android 10.

Acceso restringido a los contenidos de la pantalla.

Para proteger el contenido de la pantalla de los usuarios, Android 10 evita el acceso silencioso al contenido de la pantalla del dispositivo cambiando el alcance de los permisos READ_FRAME_BUFFER , CAPTURE_VIDEO_OUTPUT y CAPTURE_SECURE_VIDEO_OUTPUT . A partir de Android 10, estos permisos son únicamente de acceso mediante firma .
Las aplicaciones que necesitan acceder al contenido de la pantalla del dispositivo deben utilizar la API MediaProjection , que muestra un mensaje solicitando al usuario que dé su consentimiento.

Número de serie del dispositivo USB

Si su aplicación está orientada a Android 10 o superior, no puede leer el número de serie hasta que el usuario le haya otorgado permiso para acceder al dispositivo o accesorio USB.
Para obtener más información sobre cómo trabajar con dispositivos USB, consulte la guía sobre cómo configurar hosts USB .

Wifi

Las aplicaciones destinadas a Android 10 o superior no pueden habilitar ni deshabilitar Wi-Fi. El método WifiManager.setWifiEnabled() siempre devuelve false .
Si necesita solicitar a los usuarios que habiliten y deshabiliten Wi-Fi, use un panel de configuración .

Restricciones de acceso directo a redes Wi-Fi configuradas

Para proteger la privacidad del usuario, la configuración manual de la lista de redes Wi-Fi está restringida a las aplicaciones del sistema y a los controladores de políticas de dispositivos (DPC) . Un DPC determinado puede ser el propietario del dispositivo o el propietario del perfil.
Si su aplicación está orientada a Android 10 o superior y no es una aplicación del sistema ni un DPC, los siguientes métodos no devuelven datos útiles:

androide 9

Every Android release includes dozens of security enhancements to protect users. For a list of some of the major security enhancements available in Android 9, see the Android Release Notes.

androide 8

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 8.0:

  • Encryption. Added support to evict key in work profile.
  • Verified Boot. Added Android Verified Boot (AVB). Verified Boot codebase supporting rollback protection for use in boot loaders added to AOSP. Recommend bootloader support for rollback protection for the HLOS. Recommend boot loaders can only be unlocked by user physically interacting with the device.
  • Lock screen. Added support for using tamper-resistant hardware to verify lock screen credential.
  • KeyStore. Required key attestation for all devices that ship with Android 8.0+. Added ID attestation support to improve Zero Touch Enrollment.
  • Sandboxing. More tightly sandboxed many components using Project Treble's standard interface between framework and device-specific components. Applied seccomp filtering to all untrusted apps to reduce the kernel's attack surface. WebView is now run in an isolated process with very limited access to the rest of the system.
  • Kernel hardening. Implemented hardened usercopy, PAN emulation, read-only after init, and KASLR.
  • Userspace hardening. Implemented CFI for the media stack. App overlays can no longer cover system-critical windows and users have a way to dismiss them.
  • Streaming OS update. Enabled updates on devices that are are low on disk space.
  • Install unknown apps. Users must grant permission to install apps from a source that isn't a first-party app store.
  • Privacy. Android ID (SSAID) has a different value for each app and each user on the device. For web browser apps, Widevine Client ID returns a different value for each app package name and web origin. net.hostname is now empty and the dhcp client no longer sends a hostname. android.os.Build.SERIAL has been replaced with the Build.SERIAL API which is protected behind a user-controlled permission. Improved MAC address randomization in some chipsets.

androide 7

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 7.0:

  • File-based encryption. Encrypting at the file level, instead of encrypting the entire storage area as a single unit, better isolates and protects individual users and profiles (such as personal and work) on a device.
  • Direct Boot. Enabled by file-based encryption, Direct Boot allows certain apps such as alarm clock and accessibility features to run when device is powered on but not unlocked.
  • Verified Boot. Verified Boot is now strictly enforced to prevent compromised devices from booting; it supports error correction to improve reliability against non-malicious data corruption.
  • SELinux. Updated SELinux configuration and increased seccomp coverage further locks down the application sandbox and reduces attack surface.
  • Library load-order randomization and improved ASLR. Increased randomness makes some code-reuse attacks less reliable.
  • Kernel hardening. Added additional memory protection for newer kernels by marking portions of kernel memory as read-only, restricting kernel access to userspace addresses and further reducing the existing attack surface.
  • APK signature scheme v2. Introduced a whole-file signature scheme that improves verification speed and strengthens integrity guarantees.
  • Trusted CA store. To make it easier for apps to control access to their secure network traffic, user-installed certificate authorities and those installed through Device Admin APIs are no longer trusted by default for apps targeting API Level 24+. Additionally, all new Android devices must ship with the same trusted CA store.
  • Network Security Config. Configure network security and TLS through a declarative configuration file.

androide 6

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 6.0:

  • Runtime Permissions. Applications request permissions at runtime instead of being granted at App install time. Users can toggle permissions on and off for both M and pre-M applications.
  • Verified Boot. A set of cryptographic checks of system software are conducted prior to execution to ensure the phone is healthy from the bootloader all the way up to the operating system.
  • Hardware-Isolated Security. New Hardware Abstraction Layer (HAL) used by Fingerprint API, Lockscreen, Device Encryption, and Client Certificates to protect keys against kernel compromise and/or local physical attacks
  • Fingerprints. Devices can now be unlocked with just a touch. Developers can also take advantage of new APIs to use fingerprints to lock and unlock encryption keys.
  • SD Card Adoption. Removable media can be adopted to a device and expand available storage for app local data, photos, videos, etc., but still be protected by block-level encryption.
  • Clear Text Traffic. Developers can use a new StrictMode to make sure their application doesn't use cleartext.
  • System Hardening. Hardening of the system via policies enforced by SELinux. This offers better isolation between users, IOCTL filtering, reduce threat of exposed services, further tightening of SELinux domains, and extremely limited /proc access.
  • USB Access Control: Users must confirm to allow USB access to files, storage, or other functionality on the phone. Default is now charge only with access to storage requiring explicit approval from the user.

androide 5

5.0

Every Android release includes dozens of security enhancements to protect users. Here are some of the major security enhancements available in Android 5.0:

  • Encrypted by default. On devices that ship with L out-of-the-box, full disk encryption is enabled by default to improve protection of data on lost or stolen devices. Devices that update to L can be encrypted in Settings > Security.
  • Improved full disk encryption. The user password is protected against brute-force attacks using scrypt and, where available, the key is bound to the hardware keystore to prevent off-device attacks. As always, the Android screen lock secret and the device encryption key are not sent off the device or exposed to any application.
  • Android sandbox reinforced with SELinux. Android now requires SELinux in enforcing mode for all domains. SELinux is a mandatory access control (MAC) system in the Linux kernel used to augment the existing discretionary access control (DAC) security model. This new layer provides additional protection against potential security vulnerabilities.
  • Smart Lock. Android now includes trustlets that provide more flexibility for unlocking devices. For example, trustlets can allow devices to be unlocked automatically when close to another trusted device (via NFC, Bluetooth) or being used by someone with a trusted face.
  • Multi user, restricted profile, and guest modes for phones & tablets. Android now provides for multiple users on phones and includes a guest mode that can be used to provide easy temporary access to your device without granting access to your data and apps.
  • Updates to WebView without OTA. WebView can now be updated independent of the framework and without a system OTA. This will allow for faster response to potential security issues in WebView.
  • Updated cryptography for HTTPS and TLS/SSL. TLSv1.2 and TLSv1.1 is now enabled, Forward Secrecy is now preferred, AES-GCM is now enabled, and weak cipher suites (MD5, 3DES, and export cipher suites) are now disabled. See https://developer.android.com/reference/javax/net/ssl/SSLSocket.html for more details.
  • non-PIE linker support removed. Android now requires all dynamically linked executables to support PIE (position-independent executables). This enhances Android’s address space layout randomization (ASLR) implementation.
  • FORTIFY_SOURCE improvements. The following libc functions now implement FORTIFY_SOURCE protections: stpcpy(), stpncpy(), read(), recvfrom(), FD_CLR(), FD_SET(), and FD_ISSET(). This provides protection against memory-corruption vulnerabilities involving those functions.
  • Security Fixes. Android 5.0 also includes fixes for Android-specific vulnerabilities. Information about these vulnerabilities has been provided to Open Handset Alliance members, and fixes are available in Android Open Source Project. To improve security, some devices with earlier versions of Android may also include these fixes.

Android 4 y anteriores

Every Android release includes dozens of security enhancements to protect users. The following are some of the security enhancements available in Android 4.4:

  • Android sandbox reinforced with SELinux. Android now uses SELinux in enforcing mode. SELinux is a mandatory access control (MAC) system in the Linux kernel used to augment the existing discretionary access control (DAC) based security model. This provides additional protection against potential security vulnerabilities.
  • Per User VPN. On multi-user devices, VPNs are now applied per user. This can allow a user to route all network traffic through a VPN without affecting other users on the device.
  • ECDSA Provider support in AndroidKeyStore. Android now has a keystore provider that allows use of ECDSA and DSA algorithms.
  • Device Monitoring Warnings. Android provides users with a warning if any certificate has been added to the device certificate store that could allow monitoring of encrypted network traffic.
  • FORTIFY_SOURCE. Android now supports FORTIFY_SOURCE level 2, and all code is compiled with these protections. FORTIFY_SOURCE has been enhanced to work with clang.
  • Certificate Pinning. Android 4.4 detects and prevents the use of fraudulent Google certificates used in secure SSL/TLS communications.
  • Security Fixes. Android 4.4 also includes fixes for Android-specific vulnerabilities. Information about these vulnerabilities has been provided to Open Handset Alliance members and fixes are available in Android Open Source Project. To improve security, some devices with earlier versions of Android may also include these fixes.

Every Android release includes dozens of security enhancements to protect users. The following are some of the security enhancements available in Android 4.3:

  • Android sandbox reinforced with SELinux. This release strengthens the Android sandbox using the SELinux mandatory access control system (MAC) in the Linux kernel. SELinux reinforcement is invisible to users and developers, and adds robustness to the existing Android security model while maintaining compatibility with existing applications. To ensure continued compatibility this release allows the use of SELinux in a permissive mode. This mode logs any policy violations, but will not break applications or affect system behavior.
  • No setuid/setgid programs. Added support for filesystem capabilities to Android system files and removed all setuid/setguid programs.  This reduces root attack surface and the likelihood of potential security vulnerabilities.
  • ADB Authentication. Since Android 4.2.2, connections to ADB are authenticated with an RSA keypair. This prevents unauthorized use of ADB where the attacker has physical access to a device.
  • Restrict Setuid from Android Apps. The /system partition is now mounted nosuid for zygote-spawned processes, preventing Android applications from executing setuid programs. This reduces root attack surface and the likelihood of potential security vulnerabilities.
  • Capability bounding. Android zygote and ADB now use prctl(PR_CAPBSET_DROP) to drop unnecessary capabilities prior to executing applications. This prevents Android applications and applications launched from the shell from acquiring privileged capabilities.
  • AndroidKeyStore Provider. Android now has a keystore provider that allows applications to create exclusive use keys. This provides applications with an API to create or store private keys that cannot be used by other applications.
  • KeyChain isBoundKeyAlgorithm. Keychain API now provides a method (isBoundKeyType) that allows applications to confirm that system-wide keys are bound to a hardware root of trust for the device. This provides a place to create or store private keys that cannot be exported off the device, even in the event of a root compromise.
  • NO_NEW_PRIVS. Android zygote now uses prctl(PR_SET_NO_NEW_PRIVS) to block addition of new privileges prior to execution application code. This prevents Android applications from performing operations which can elevate privileges via execve. (This requires Linux kernel version 3.5 or greater).
  • FORTIFY_SOURCE enhancements. Enabled FORTIFY_SOURCE on Android x86 and MIPS and fortified strchr(), strrchr(), strlen(), and umask() calls. This can detect potential memory corruption vulnerabilities or unterminated string constants.
  • Relocation protections. Enabled read only relocations (relro) for statically linked executables and removed all text relocations in Android code. This provides defense in depth against potential memory corruption vulnerabilities.
  • Improved EntropyMixer. EntropyMixer now writes entropy at shutdown / reboot, in addition to periodic mixing. This allows retention of all entropy generated while devices are powered on, and is especially useful for devices that are rebooted immediately after provisioning.
  • Security Fixes. Android 4.3 also includes fixes for Android-specific vulnerabilities. Information about these vulnerabilities has been provided to Open Handset Alliance members and fixes are available in Android Open Source Project. To improve security, some devices with earlier versions of Android may also include these fixes.

Android provides a multi-layered security model described in the Android Security Overview. Each update to Android includes dozens of security enhancements to protect users. The following are some of the security enhancements introduced in Android 4.2:

  • Application verification - Users can choose to enable “Verify Apps" and have applications screened by an application verifier, prior to installation. App verification can alert the user if they try to install an app that might be harmful; if an application is especially bad, it can block installation.
  • More control of premium SMS - Android will provide a notification if an application attempts to send SMS to a short code that uses premium services which might cause additional charges. The user can choose whether to allow the application to send the message or block it.
  • Always-on VPN - VPN can be configured so that applications will not have access to the network until a VPN connection is established. This prevents applications from sending data across other networks.
  • Certificate Pinning - The Android core libraries now support certificate pinning. Pinned domains will receive a certificate validation failure if the certificate does not chain to a set of expected certificates. This protects against possible compromise of Certificate Authorities.
  • Improved display of Android permissions - Permissions have been organized into groups that are more easily understood by users. During review of the permissions, the user can click on the permission to see more detailed information about the permission.
  • installd hardening - The installd daemon does not run as the root user, reducing potential attack surface for root privilege escalation.
  • init script hardening - init scripts now apply O_NOFOLLOW semantics to prevent symlink related attacks.
  • FORTIFY_SOURCE - Android now implements FORTIFY_SOURCE. This is used by system libraries and applications to prevent memory corruption.
  • ContentProvider default configuration - Applications which target API level 17 will have "export" set to "false" by default for each Content Provider, reducing default attack surface for applications.
  • Cryptography - Modified the default implementations of SecureRandom and Cipher.RSA to use OpenSSL. Added SSL Socket support for TLSv1.1 and TLSv1.2 using OpenSSL 1.0.1
  • Security Fixes - Upgraded open source libraries with security fixes include WebKit, libpng, OpenSSL, and LibXML. Android 4.2 also includes fixes for Android-specific vulnerabilities. Information about these vulnerabilities has been provided to Open Handset Alliance members and fixes are available in Android Open Source Project. To improve security, some devices with earlier versions of Android may also include these fixes.

Android provides a multi-layered security model described in the Android Security Overview. Each update to Android includes dozens of security enhancements to protect users. The following are some of the security enhancements introduced in Android versions 1.5 through 4.1:

Android 1.5
  • ProPolice to prevent stack buffer overruns (-fstack-protector)
  • safe_iop to reduce integer overflows
  • Extensions to OpenBSD dlmalloc to prevent double free() vulnerabilities and to prevent chunk consolidation attacks. Chunk consolidation attacks are a common way to exploit heap corruption.
  • OpenBSD calloc to prevent integer overflows during memory allocation
Android 2.3
  • Format string vulnerability protections (-Wformat-security -Werror=format-security)
  • Hardware-based No eXecute (NX) to prevent code execution on the stack and heap
  • Linux mmap_min_addr to mitigate null pointer dereference privilege escalation (further enhanced in Android 4.1)
Android 4.0
Address Space Layout Randomization (ASLR) to randomize key locations in memory
Android 4.1
  • PIE (Position Independent Executable) support
  • Read-only relocations / immediate binding (-Wl,-z,relro -Wl,-z,now)
  • dmesg_restrict enabled (avoid leaking kernel addresses)
  • kptr_restrict enabled (avoid leaking kernel addresses)