Miglioramenti della sicurezza

Android migliora continuamente le sue capacità e offerte di sicurezza. Visualizza gli elenchi dei miglioramenti per versione nella barra di navigazione a sinistra.

Androide 14

Ogni versione di Android include decine di miglioramenti alla sicurezza per proteggere gli utenti. Ecco alcuni dei principali miglioramenti della sicurezza disponibili in Android 14:

  • AddressSanitizer assistito da hardware (HWASan), introdotto in Android 10, è uno strumento di rilevamento degli errori di memoria simile a AddressSanitizer . Android 14 apporta miglioramenti significativi a HWASan. Scopri come aiuta a impedire che i bug arrivino nelle versioni Android, HWAddressSanitizer
  • In Android 14, a partire dalle app che condividono dati sulla posizione con terze parti, la finestra di dialogo delle autorizzazioni di runtime del sistema ora include una sezione cliccabile che evidenzia le pratiche di condivisione dei dati dell'app, comprese informazioni sul motivo per cui un'app potrebbe decidere di condividere dati con terze parti .
  • Android 12 ha introdotto un'opzione per disabilitare il supporto 2G a livello di modem, che protegge gli utenti dal rischio per la sicurezza intrinseco derivante dal modello di sicurezza obsoleto del 2G. Riconoscendo quanto potrebbe essere fondamentale la disattivazione del 2G per i clienti aziendali, Android 14 abilita questa funzionalità di sicurezza in Android Enterprise, introducendo il supporto per gli amministratori IT per limitare la capacità di un dispositivo gestito di effettuare il downgrade alla connettività 2G .
  • Aggiunto supporto per rifiutare connessioni cellulari con cifratura nulla, garantendo che il traffico vocale e SMS a commutazione di circuito sia sempre crittografato e protetto dall'intercettazione passiva via etere. Ulteriori informazioni sul programma di Android per rafforzare la connettività cellulare .
  • Aggiunto il supporto per più IMEI
  • A partire da Android 14, AES-HCTR2 è la modalità preferita di crittografia dei nomi di file per i dispositivi con istruzioni di crittografia accelerata.
  • Connettività cellulare
  • Documentazione aggiunta per il Centro sicurezza Android
  • Se la tua app è destinata ad Android 14 e utilizza il caricamento dinamico del codice (DCL), tutti i file caricati dinamicamente devono essere contrassegnati come di sola lettura. Altrimenti il ​​sistema lancia un'eccezione. Consigliamo alle app di evitare il caricamento dinamico del codice quando possibile, poiché ciò aumenta notevolmente il rischio che un'app possa essere compromessa dall'iniezione di codice o dalla manomissione del codice.

Consulta le nostre note di rilascio AOSP complete e l' elenco delle funzionalità e delle modifiche per sviluppatori Android.

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

Ogni versione di Android include decine di miglioramenti alla sicurezza per proteggere gli utenti. Ecco alcuni dei principali miglioramenti della sicurezza disponibili in Android 12:

  • Android 12 introduce l' API BiometricManager.Strings , che fornisce stringhe localizzate per le app che utilizzano BiometricPrompt per l'autenticazione. Queste stringhe sono destinate a riconoscere il dispositivo e a fornire maggiore specificità sui tipi di autenticazione che possono essere utilizzati. Android 12 include anche il supporto per i sensori di impronte digitali sotto il display
  • Aggiunto supporto per sensori di impronte digitali sotto il display
  • Introduzione del Fingerprint Android Interface Definition Language (AIDL)
  • Supporto per il nuovo Face AIDL
  • Introduzione di Rust come linguaggio per lo sviluppo di piattaforme
  • Aggiunta l'opzione per consentire agli utenti di concedere l'accesso solo alla loro posizione approssimativa
  • Aggiunti indicatori di privacy sulla barra di stato quando un'app utilizza la fotocamera o il microfono
  • Private Compute Core (PCC) di Android
  • Aggiunta un'opzione per disabilitare il supporto 2G

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

Every Android release includes dozens of security enhancements to protect users. Android 10 includes several security and privacy enhancements. See the Android 10 release notes for a complete list of changes in Android 10.

Security

BoundsSanitizer

Android 10 deploys BoundsSanitizer (BoundSan) in Bluetooth and codecs. BoundSan uses UBSan's bounds sanitizer. This mitigation is enabled on a per-module level. It helps keep critical components of Android secure and shouldn't be disabled. BoundSan is enabled in the following codecs:

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

Execute-only memory

By default, executable code sections for AArch64 system binaries are marked execute-only (nonreadable) as a hardening mitigation against just-in-time code reuse attacks. Code that mixes data and code together and code that purposefully inspects these sections (without first remapping the memory segments as readable) no longer functions. Apps with a target SDK of Android 10 (API level 29 or higher) are impacted if the app attempts to read code sections of execute-only memory (XOM) enabled system libraries in memory without first marking the section as readable.

Extended access

Trust agents, the underlying mechanism used by tertiary authentication mechanisms such as Smart Lock, can only extend unlock in Android 10. Trust agents can no longer unlock a locked device and can only keep a device unlocked for a maximum of four hours.

Face authentication

Face authentication allows users to unlock their device simply by looking at the front of their device. Android 10 adds support for a new face authentication stack that can securely process camera frames, preserving security and privacy during face authentication on supported hardware. Android 10 also provides an easy way for security-compliant implementations to enable app integration for transactions such as online banking or other services.

Integer Overflow Sanitization

Android 10 enables Integer Overflow Sanitization (IntSan) in software codecs. Ensure that playback performance is acceptable for any codecs that aren't supported in the device's hardware. IntSan is enabled in the following codecs:

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

Modular system components

Android 10 modularizes some Android system components and enables them to be updated outside of the normal Android release cycle. Some modules include:

OEMCrypto

Android 10 uses OEMCrypto API version 15.

Scudo

Scudo is a dynamic user-mode memory allocator designed to be more resilient against heap-related vulnerabilities. It provides the standard C allocation and deallocation primitives, as well as the C++ primitives.

ShadowCallStack

ShadowCallStack (SCS) is an LLVM instrumentation mode that protects against return address overwrites (like stack buffer overflows) by saving a function's return address to a separately allocated ShadowCallStack instance in the function prolog of nonleaf functions and loading the return address from the ShadowCallStack instance in the function epilog.

WPA3 and Wi-Fi Enhanced Open

Android 10 adds support for the Wi-Fi Protected Access 3 (WPA3) and Wi-Fi Enhanced Open security standards to provide better privacy and robustness against known attacks.

Privacy

App access when targeting Android 9 or lower

If your app runs on Android 10 or higher but targets Android 9 (API level 28) or lower, the platform applies the following behavior:

  • If your app declares a <uses-permission> element for either ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION, the system automatically adds a <uses-permission> element for ACCESS_BACKGROUND_LOCATION during installation.
  • If your app requests either ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION, the system automatically adds ACCESS_BACKGROUND_LOCATION to the request.

Background activity restrictions

Starting in Android 10, the system places restrictions on starting activities from the background. This behavior change helps minimize interruptions for the user and keeps the user more in control of what's shown on their screen. As long as your app starts activities as a direct result of user interaction, your app most likely isn't affected by these restrictions.
To learn more about the recommended alternative to starting activities from the background, see the guide on how to alert users of time-sensitive events in your app.

Camera metadata

Android 10 changes the breadth of information that the getCameraCharacteristics() method returns by default. In particular, your app must have the CAMERA permission in order to access potentially device-specific metadata that is included in this method's return value.
To learn more about these changes, see the section about camera fields that require permission.

Clipboard data

Unless your app is the default input method editor (IME) or is the app that currently has focus, your app cannot access clipboard data on Android 10 or higher.

Device location

To support the additional control that users have over an app's access to location information, Android 10 introduces the ACCESS_BACKGROUND_LOCATION permission.
Unlike the ACCESS_FINE_LOCATION and ACCESS_COARSE_LOCATION permissions, the ACCESS_BACKGROUND_LOCATION permission only affects an app's access to location when it runs in the background. An app is considered to be accessing location in the background unless one of the following conditions is satisfied:

  • An activity belonging to the app is visible.
  • The app is running a foreground service that has declared a foreground service type of location.
    To declare the foreground service type for a service in your app, set your app's targetSdkVersion or compileSdkVersion to 29 or higher. Learn more about how foreground services can continue user-initiated actions that require access to location.

External storage

By default, apps targeting Android 10 and higher are given scoped access into external storage, or scoped storage. Such apps can see the following types of files within an external storage device without needing to request any storage-related user permissions:

To learn more about scoped storage, as well as how to share, access, and modify files that are saved on external storage devices, see the guides on how to manage files in external storage and access and modify media files.

MAC address randomization

On devices that run Android 10 or higher, the system transmits randomized MAC addresses by default.
If your app handles an enterprise use case, the platform provides APIs for several operations related to MAC addresses:

  • Obtain randomized MAC address: Device owner apps and profile owner apps can retrieve the randomized MAC address assigned to a specific network by calling getRandomizedMacAddress().
  • Obtain actual, factory MAC address: Device owner apps can retrieve a device's actual hardware MAC address by calling getWifiMacAddress(). This method is useful for tracking fleets of devices.

Non-resettable device identifiers

Starting in Android 10, apps must have the READ_PRIVILEGED_PHONE_STATE privileged permission in order to access the device's non-resettable identifiers, which include both IMEI and serial number.

If your app doesn't have the permission and you try asking for information about non-resettable identifiers anyway, the platform's response varies based on target SDK version:

  • If your app targets Android 10 or higher, a SecurityException occurs.
  • If your app targets Android 9 (API level 28) or lower, the method returns null or placeholder data if the app has the READ_PHONE_STATE permission. Otherwise, a SecurityException occurs.

Physical activity recognition

Android 10 introduces the android.permission.ACTIVITY_RECOGNITION runtime permission for apps that need to detect the user's step count or classify the user's physical activity, such as walking, biking, or moving in a vehicle. This is designed to give users visibility of how device sensor data is used in Settings.
Some libraries within Google Play services, such as the Activity Recognition API and the Google Fit API, don't provide results unless the user has granted your app this permission.
The only built-in sensors on the device that require you to declare this permission are the step counter and step detector sensors.
If your app targets Android 9 (API level 28) or lower, the system auto-grants the android.permission.ACTIVITY_RECOGNITION permission to your app, as needed, if your app satisfies each of the following conditions:

  • The manifest file includes the com.google.android.gms.permission.ACTIVITY_RECOGNITION permission.
  • The manifest file doesn't include the android.permission.ACTIVITY_RECOGNITION permission.

If the system-auto grants the android.permission.ACTIVITY_RECOGNITION permission, your app retains the permission after you update your app to target Android 10. However, the user can revoke this permission at any time in system settings.

/proc/net filesystem restrictions

On devices that run Android 10 or higher, apps cannot access /proc/net, which includes information about a device's network state. Apps that need access to this information, such as VPNs, should use the NetworkStatsManager or ConnectivityManager class.

Permission groups removed from UI

As of Android 10, apps cannot look up how permissions are grouped in the UI.

Removal of contacts affinity

Starting in Android 10, the platform doesn't keep track of contacts affinity information. As a result, if your app conducts a search on the user's contacts, the results aren't ordered by frequency of interaction.
The guide about ContactsProvider contains a notice describing the specific fields and methods that are obsolete on all devices starting in Android 10.

Restricted access to screen contents

To protect users' screen contents, Android 10 prevents silent access to the device's screen contents by changing the scope of the READ_FRAME_BUFFER, CAPTURE_VIDEO_OUTPUT, and CAPTURE_SECURE_VIDEO_OUTPUT permissions. As of Android 10, these permissions are signature-access only.
Apps that need to access the device's screen contents should use the MediaProjection API, which displays a prompt asking the user to provide consent.

USB device serial number

If your app targets Android 10 or higher, your app cannot read the serial number until the user has granted your app permission to access the USB device or accessory.
To learn more about working with USB devices, see the guide on how to configure USB hosts.

Wi-Fi

Apps targeting Android 10 or higher cannot enable or disable Wi-Fi. The WifiManager.setWifiEnabled() method always returns false.
If you need to prompt users to enable and disable Wi-Fi, use a settings panel.

Restrictions on direct access to configured Wi-Fi networks

To protect user privacy, manual configuration of the list of Wi-Fi networks is restricted to system apps and device policy controllers (DPCs). A given DPC can be either the device owner or the profile owner.
If your app targets Android 10 or higher, and it isn't a system app or a DPC, then the following methods don't return useful data:

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.

Androide7

Ogni versione di Android include dozzine di miglioramenti della sicurezza per proteggere gli utenti. Ecco alcuni dei principali miglioramenti della sicurezza disponibili in Android 7.0:

  • Crittografia basata su file . La crittografia a livello di file, invece di crittografare l'intera area di archiviazione come una singola unità, isola e protegge meglio i singoli utenti e profili (come quelli personali e di lavoro) su un dispositivo.
  • Avvio diretto . Abilitato dalla crittografia basata su file, Direct Boot consente l'esecuzione di alcune app come la sveglia e le funzioni di accessibilità quando il dispositivo è acceso ma non sbloccato.
  • Stivale verificato . L'avvio verificato è ora rigorosamente applicato per impedire l'avvio dei dispositivi compromessi; supporta la correzione degli errori per migliorare l'affidabilità contro il danneggiamento dei dati non dannoso.
  • SELinux . La configurazione SELinux aggiornata e la maggiore copertura seccomp bloccano ulteriormente la sandbox dell'applicazione e riducono la superficie di attacco.
  • Randomizzazione dell'ordine di caricamento della libreria e ASLR migliorato . La maggiore casualità rende meno affidabili alcuni attacchi di riutilizzo del codice.
  • Indurimento del kernel . Aggiunta una protezione aggiuntiva della memoria per i kernel più recenti contrassegnando porzioni di memoria del kernel come di sola lettura, limitando l'accesso del kernel agli indirizzi dello spazio utente e riducendo ulteriormente la superficie di attacco esistente.
  • Schema di firma APK v2 . Introdotto uno schema di firma dell'intero file che migliora la velocità di verifica e rafforza le garanzie di integrità.
  • Archivio CA affidabile . Per consentire alle app di controllare più facilmente l'accesso al proprio traffico di rete protetto, le autorità di certificazione installate dagli utenti e quelle installate tramite le API di amministrazione del dispositivo non sono più considerate attendibili per impostazione predefinita per le app destinate al livello API 24+. Inoltre, tutti i nuovi dispositivi Android devono essere spediti con lo stesso archivio CA affidabile.
  • Configurazione sicurezza di rete . Configura la sicurezza di rete e TLS tramite un file di configurazione dichiarativo.

Androide 6

Ogni versione di Android include dozzine di miglioramenti della sicurezza per proteggere gli utenti. Ecco alcuni dei principali miglioramenti della sicurezza disponibili in Android 6.0:

  • Autorizzazioni di runtime . Le applicazioni richiedono autorizzazioni in fase di esecuzione anziché essere concesse al momento dell'installazione dell'app. Gli utenti possono attivare e disattivare le autorizzazioni sia per le applicazioni M che per quelle pre-M.
  • Stivale verificato . Prima dell'esecuzione viene eseguita una serie di controlli crittografici del software di sistema per garantire che il telefono sia integro dal bootloader fino al sistema operativo.
  • Sicurezza isolata dall'hardware . Nuovo Hardware Abstraction Layer (HAL) utilizzato da Fingerprint API, Lockscreen, Device Encryption e Client Certificates per proteggere le chiavi dalla compromissione del kernel e/o da attacchi fisici locali
  • Impronte digitali . I dispositivi ora possono essere sbloccati con un semplice tocco. Gli sviluppatori possono anche sfruttare le nuove API per utilizzare le impronte digitali per bloccare e sbloccare le chiavi di crittografia.
  • Adozione scheda SD . I supporti rimovibili possono essere adottati su un dispositivo ed espandere lo spazio di archiviazione disponibile per dati locali dell'app, foto, video, ecc., ma essere comunque protetti dalla crittografia a livello di blocco.
  • Traffico di testo in chiaro . Gli sviluppatori possono utilizzare un nuovo StrictMode per assicurarsi che la loro applicazione non utilizzi il testo in chiaro.
  • Rafforzamento del sistema . Rafforzamento del sistema tramite le politiche imposte da SELinux. Ciò offre un migliore isolamento tra gli utenti, il filtraggio IOCTL, riduce la minaccia dei servizi esposti, un ulteriore restringimento dei domini SELinux e un accesso /proc estremamente limitato.
  • Controllo dell'accesso USB: gli utenti devono confermare per consentire l'accesso USB a file, archiviazione o altre funzionalità sul telefono. L'impostazione predefinita ora è addebitata solo con l'accesso allo spazio di archiviazione che richiede l'approvazione esplicita dell'utente.

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 e versioni precedenti

Ogni versione di Android include dozzine di miglioramenti della sicurezza per proteggere gli utenti. Di seguito sono riportati alcuni dei miglioramenti della sicurezza disponibili in Android 4.4:

  • Sandbox Android rinforzato con SELinux. Android ora utilizza SELinux in modalità di applicazione. SELinux è un sistema di controllo dell'accesso (MAC) obbligatorio nel kernel Linux utilizzato per aumentare il modello di sicurezza basato sul controllo dell'accesso discrezionale (DAC) esistente. Ciò fornisce una protezione aggiuntiva contro potenziali vulnerabilità della sicurezza.
  • VPN per utente. Sui dispositivi multiutente, le VPN vengono ora applicate per utente. Ciò può consentire a un utente di instradare tutto il traffico di rete attraverso una VPN senza influire sugli altri utenti sul dispositivo.
  • Supporto del provider ECDSA in AndroidKeyStore. Android dispone ora di un provider di keystore che consente l'utilizzo di algoritmi ECDSA e DSA.
  • Avvisi di monitoraggio del dispositivo. Android fornisce agli utenti un avviso se è stato aggiunto un certificato all'archivio certificati del dispositivo che potrebbe consentire il monitoraggio del traffico di rete crittografato.
  • FORTIFY_SOURCE. Android ora supporta FORTIFY_SOURCE livello 2 e tutto il codice viene compilato con queste protezioni. FORTIFY_SOURCE è stato migliorato per funzionare con clang.
  • Appuntamento del certificato. Android 4.4 rileva e previene l'uso di certificati Google fraudolenti utilizzati nelle comunicazioni SSL/TLS sicure.
  • Correzioni di sicurezza. Android 4.4 include anche correzioni per vulnerabilità specifiche di Android. Le informazioni su queste vulnerabilità sono state fornite ai membri di Open Handset Alliance e le correzioni sono disponibili in Android Open Source Project. Per migliorare la sicurezza, anche alcuni dispositivi con versioni precedenti di Android potrebbero includere queste correzioni.

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 fornisce un modello di sicurezza a più livelli descritto nella Panoramica sulla sicurezza di Android . Ogni aggiornamento ad Android include dozzine di miglioramenti della sicurezza per proteggere gli utenti. Di seguito sono riportati alcuni dei miglioramenti della sicurezza introdotti nelle versioni di Android da 1.5 a 4.1:

Android 1.5
  • ProPolice per prevenire il sovraccarico del buffer dello stack (-fstack-protector)
  • safe_iop per ridurre gli overflow di numeri interi
  • Estensioni a OpenBSD dlmalloc per prevenire le vulnerabilità double free() e per prevenire gli attacchi di consolidamento dei blocchi. Gli attacchi di consolidamento dei blocchi sono un modo comune per sfruttare la corruzione dell'heap.
  • Calloc OpenBSD per prevenire overflow di interi durante l'allocazione della memoria
Android 2.3
  • Formatta le protezioni dalle vulnerabilità delle stringhe (-Wformat-security -Werror=format-security)
  • Basato su hardware No eXecute (NX) per impedire l'esecuzione di codice nello stack e nell'heap
  • Linux mmap_min_addr per mitigare l'escalation dei privilegi di dereference del puntatore nullo (ulteriormente migliorato in Android 4.1)
Android 4.0
Address Space Layout Randomization (ASLR) per randomizzare le posizioni chiave nella memoria
Android 4.1
  • Supporto PIE (Position Independent Executable).
  • Riposizionamento di sola lettura/associazione immediata (-Wl,-z,relro -Wl,-z,now)
  • dmesg_restrict abilitato (evita la perdita di indirizzi del kernel)
  • kptr_restrict abilitato (evita la perdita di indirizzi del kernel)