Sicherheitsverbesserungen

Android verbessert kontinuierlich seine Sicherheitsfähigkeiten und -angebote. Sehen Sie sich die Listen der Verbesserungen nach Release in der linken Navigation an.

Android 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.

Android 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.

Android 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

Android 11

Jede Android-Version enthält Dutzende von Sicherheitsverbesserungen zum Schutz der Benutzer. Eine Liste einiger der wichtigsten Sicherheitsverbesserungen, die in Android 11 verfügbar sind, finden Sie in den Android-Versionshinweisen .

Android 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:

Android 9

Jede Android-Version enthält Dutzende von Sicherheitsverbesserungen zum Schutz der Benutzer. Eine Liste einiger der wichtigsten Sicherheitsverbesserungen, die in Android 9 verfügbar sind, finden Sie in den Android-Versionshinweisen .

Android 8

Jede Android-Version enthält Dutzende von Sicherheitsverbesserungen zum Schutz der Benutzer. Hier sind einige der wichtigsten Sicherheitsverbesserungen, die in Android 8.0 verfügbar sind:

  • Verschlüsselung . Unterstützung zum Entfernen von Schlüsseln im Arbeitsprofil hinzugefügt.
  • Verifizierter Start . Android Verified Boot (AVB) hinzugefügt. Verifizierte Boot-Codebasis, die Rollback-Schutz für die Verwendung in Bootloadern unterstützt, die zu AOSP hinzugefügt wurden. Empfehlen Sie Bootloader-Unterstützung für Rollback-Schutz für das HLOS. Empfohlene Bootloader können nur durch physische Interaktion des Benutzers mit dem Gerät entsperrt werden.
  • Bildschirm sperren . Unterstützung für die Verwendung manipulationssicherer Hardware zur Überprüfung der Anmeldeinformationen für den Sperrbildschirm hinzugefügt.
  • Schlüsselspeicher . Erforderlicher Schlüsselnachweis für alle Geräte, die mit Android 8.0+ ausgeliefert werden. ID-Beglaubigungsunterstützung hinzugefügt, um die Zero-Touch-Registrierung zu verbessern.
  • Sandboxing . Engere Sandboxing vieler Komponenten unter Verwendung der Standardschnittstelle von Project Treble zwischen Framework und gerätespezifischen Komponenten. Seccomp-Filterung auf alle nicht vertrauenswürdigen Apps angewendet, um die Angriffsfläche des Kernels zu reduzieren. WebView wird jetzt in einem isolierten Prozess mit sehr eingeschränktem Zugriff auf den Rest des Systems ausgeführt.
  • Kernhärtung . Implementierte gehärtete Benutzerkopie , PAN-Emulation, schreibgeschützt nach Init und KASLR.
  • Userspace-Härtung . CFI für den Medienstapel implementiert. App-Overlays können systemkritische Fenster nicht mehr abdecken und Benutzer haben eine Möglichkeit, sie zu schließen.
  • Streaming-OS-Update . Aktivierte Updates auf Geräten mit wenig Speicherplatz.
  • Installieren Sie unbekannte Apps . Benutzer müssen die Berechtigung zum Installieren von Apps aus einer Quelle erteilen , die kein Erstanbieter-App-Store ist.
  • Datenschutz . Die Android-ID (SSAID) hat für jede App und jeden Benutzer auf dem Gerät einen anderen Wert. Für Webbrowser-Apps gibt Widevine Client ID einen anderen Wert für jeden App-Paketnamen und Webursprung zurück. net.hostname ist jetzt leer und der DHCP-Client sendet keinen Hostnamen mehr. android.os.Build.SERIAL wurde durch die Build.SERIAL -API ersetzt, die hinter einer benutzergesteuerten Berechtigung geschützt ist. Verbesserte Randomisierung von MAC-Adressen in einigen Chipsätzen.

Android 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.

Android 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.

Android 5

5,0

Jede Android-Version enthält Dutzende von Sicherheitsverbesserungen zum Schutz der Benutzer. Hier sind einige der wichtigsten Sicherheitsverbesserungen, die in Android 5.0 verfügbar sind:

  • Standardmäßig verschlüsselt. Auf Geräten, die standardmäßig mit L ausgeliefert werden, ist die vollständige Festplattenverschlüsselung standardmäßig aktiviert, um den Schutz von Daten auf verlorenen oder gestohlenen Geräten zu verbessern. Geräte, die auf L aktualisiert werden, können unter Einstellungen > Sicherheit verschlüsselt werden.
  • Verbesserte Festplattenverschlüsselung. Das Benutzerkennwort wird mithilfe von scrypt vor Brute-Force-Angriffen geschützt, und der Schlüssel ist, sofern verfügbar, an den Hardware-Schlüsselspeicher gebunden, um Angriffe außerhalb des Geräts zu verhindern. Wie immer werden das Android-Bildschirmsperrgeheimnis und der Geräteverschlüsselungsschlüssel nicht vom Gerät gesendet oder einer Anwendung ausgesetzt.
  • Android-Sandbox verstärkt mit SELinux . Android erfordert jetzt SELinux im Erzwingungsmodus für alle Domänen. SELinux ist ein MAC-System (Mandatory Access Control) im Linux-Kernel, das zur Erweiterung des bestehenden Sicherheitsmodells Discretionary Access Control (DAC) verwendet wird. Diese neue Schicht bietet zusätzlichen Schutz vor potenziellen Sicherheitslücken.
  • Intelligentes Schloss. Android enthält jetzt Trustlets, die mehr Flexibilität beim Entsperren von Geräten bieten. Beispielsweise können Trustlets ermöglichen, dass Geräte automatisch entsperrt werden, wenn sie sich in der Nähe eines anderen vertrauenswürdigen Geräts (über NFC, Bluetooth) befinden oder von jemandem mit einem vertrauenswürdigen Gesicht verwendet werden.
  • Mehrbenutzer-, eingeschränktes Profil- und Gastmodus für Telefone und Tablets. Android bietet jetzt mehrere Benutzer auf Telefonen und enthält einen Gastmodus, der verwendet werden kann, um einen einfachen temporären Zugriff auf Ihr Gerät zu ermöglichen, ohne Zugriff auf Ihre Daten und Apps zu gewähren.
  • Updates auf WebView ohne OTA. WebView kann nun unabhängig vom Framework und ohne System-OTA aktualisiert werden. Dies ermöglicht eine schnellere Reaktion auf potenzielle Sicherheitsprobleme in WebView.
  • Aktualisierte Kryptografie für HTTPS und TLS/SSL. TLSv1.2 und TLSv1.1 sind jetzt aktiviert, Forward Secrecy wird jetzt bevorzugt, AES-GCM ist jetzt aktiviert und schwache Verschlüsselungssammlungen (MD5, 3DES und Export-Verschlüsselungssammlungen) sind jetzt deaktiviert. Weitere Einzelheiten finden Sie unter https://developer.android.com/reference/javax/net/ssl/SSLSocket.html .
  • Nicht-PIE-Linker-Unterstützung entfernt. Android erfordert jetzt, dass alle dynamisch verknüpften ausführbaren Dateien PIE (positionsunabhängige ausführbare Dateien) unterstützen. Dies verbessert die Implementierung der Adressraum-Layout-Randomisierung (ASLR) von Android.
  • FORTIFY_SOURCE-Verbesserungen. Die folgenden libc-Funktionen implementieren jetzt FORTIFY_SOURCE-Schutz: stpcpy() , stpncpy() , read() , recvfrom() , FD_CLR() , FD_SET() und FD_ISSET() . Dies bietet Schutz vor Speicherbeschädigungsschwachstellen, die diese Funktionen betreffen.
  • Sicherheitskorrekturen. Android 5.0 enthält auch Korrekturen für Android-spezifische Schwachstellen. Informationen zu diesen Schwachstellen wurden Mitgliedern der Open Handset Alliance bereitgestellt, und Korrekturen sind im Android Open Source Project verfügbar. Um die Sicherheit zu verbessern, enthalten einige Geräte mit früheren Android-Versionen möglicherweise auch diese Korrekturen.

Android 4 und niedriger

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 bietet ein mehrschichtiges Sicherheitsmodell, das in der Android-Sicherheitsübersicht beschrieben wird. Jedes Update für Android enthält Dutzende von Sicherheitsverbesserungen zum Schutz der Benutzer. Im Folgenden sind einige der Sicherheitsverbesserungen aufgeführt, die in Android 4.2 eingeführt wurden:

  • Anwendungsverifizierung – Benutzer können „Apps verifizieren“ aktivieren und Anwendungen vor der Installation von einem Anwendungsverifizierer überprüfen lassen. Die App-Verifizierung kann den Benutzer warnen, wenn er versucht, eine App zu installieren, die schädlich sein könnte; wenn eine Anwendung besonders schlecht ist, es kann die Installation blockieren.
  • Mehr Kontrolle über Premium-SMS – Android gibt eine Benachrichtigung aus, wenn eine Anwendung versucht, SMS an eine Kurzwahl zu senden, die Premium-Dienste verwendet, die zusätzliche Gebühren verursachen können. Der Benutzer kann wählen, ob er der Anwendung das Senden der Nachricht erlauben oder sie blockieren möchte.
  • Always-On-VPN – VPN kann so konfiguriert werden, dass Anwendungen keinen Zugriff auf das Netzwerk haben, bis eine VPN-Verbindung hergestellt ist. Dadurch wird verhindert, dass Anwendungen Daten über andere Netzwerke senden.
  • Zertifikat-Pinning – Die Android-Core-Bibliotheken unterstützen jetzt das Zertifikat-Pinning . Angeheftete Domänen erhalten einen Zertifikatvalidierungsfehler, wenn das Zertifikat nicht mit einem Satz erwarteter Zertifikate verkettet ist. Dies schützt vor einer möglichen Kompromittierung von Zertifizierungsstellen.
  • Verbesserte Anzeige von Android-Berechtigungen – Berechtigungen wurden in Gruppen organisiert, die für Benutzer leichter verständlich sind. Während der Überprüfung der Berechtigungen kann der Benutzer auf die Berechtigung klicken, um detailliertere Informationen über die Berechtigung anzuzeigen.
  • installd-Härtung – Der installd Daemon wird nicht als Root-Benutzer ausgeführt, wodurch die potenzielle Angriffsfläche für die Eskalation von Root-Berechtigungen verringert wird.
  • Härtung von Init-Skripten - Init-Skripte wenden jetzt die O_NOFOLLOW Semantik an, um Angriffe im Zusammenhang mit Symlinks zu verhindern.
  • FORTIFY_SOURCE – Android implementiert jetzt FORTIFY_SOURCE . Dies wird von Systembibliotheken und Anwendungen verwendet, um Speicherbeschädigungen zu verhindern.
  • ContentProvider-Standardkonfiguration – Bei Anwendungen, die auf API-Ebene 17 abzielen, ist „export“ standardmäßig für jeden Content Provider auf „false“ gesetzt, wodurch die Standardangriffsfläche für Anwendungen reduziert wird.
  • Kryptografie – Die Standardimplementierungen von SecureRandom und Cipher.RSA wurden geändert, um OpenSSL zu verwenden. SSL-Socket-Unterstützung für TLSv1.1 und TLSv1.2 mit OpenSSL 1.0.1 hinzugefügt
  • Sicherheitsfixes – Aktualisierte Open-Source-Bibliotheken mit Sicherheitsfixes umfassen WebKit, libpng, OpenSSL und LibXML. Android 4.2 enthält auch Korrekturen für Android-spezifische Sicherheitslücken. Informationen zu diesen Sicherheitslücken wurden Mitgliedern der Open Handset Alliance bereitgestellt, und Korrekturen sind im Android Open Source Project verfügbar. Um die Sicherheit zu verbessern, enthalten einige Geräte mit früheren Android-Versionen möglicherweise auch diese Korrekturen.

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)