보안 기능 향상

Android는 보안 기능과 서비스를 지속적으로 개선합니다. 왼쪽 탐색 메뉴에서 버전별 기능 향상 목록을 참고하세요.

Android 14

모든 Android 버전에는 사용자를 보호하기 위한 수십 가지 보안 개선사항이 포함되어 있습니다. 다음은 Android 14에서 사용할 수 있는 주요 보안 향상 기능 중 일부입니다.

  • Android 10에서 도입된 하드웨어 지원 AddressSanitizer(HWASan)은 AddressSanitizer와 유사한 메모리 오류 감지 도구입니다. Android 14에서는 HWASan이 크게 개선됩니다. HWASan이 어떻게 버그가 Android 버전, HWAddressSanitizer에 들어가지 못하도록 방지하는지 알아보세요.
  • Android 14에서는 서드 파티와 위치 데이터를 공유하는 앱부터 시스템 런타임 권한 대화상자에 이제 앱의 데이터 공유 관행을 강조하는 섹션이 포함됩니다. 클릭 가능한 이 섹션에는 앱에서 서드 파티와 데이터를 공유하겠다는 판단을 내릴 수 있는 이유 등의 정보가 포함됩니다.
  • Android 12에서는 모델 수준에서 2G 지원을 사용 중지하는 옵션이 도입되었습니다. 이 옵션은 더 이상 사용되지 않는 2G의 보안 모델에 내재된 보안 위험으로부터 사용자를 보호합니다. Android 14에서는 2G 사용 중지가 기업 고객에게 매우 중요하다는 사실에 대한 인식을 기반으로 Android Enterprise에 이 보안 기능을 사용 설정했으며 IT 관리자가 관리 기기에서 2G 연결로 다운그레이드할 수 있는 기능을 제한할 수 있는 지원을 도입했습니다.
  • null 암호화된 모바일 데이터 연결 거부에 대한 지원이 추가되었습니다. 이를 통해 회로에서 전환된 음성 및 SMS 트래픽이 언제나 암호화되며 수동적인 무선 업데이트 가로채기로부터 보호됩니다. 모바일 데이터 연결을 강화하기 위한 Android의 프로그램에 관해 자세히 알아보세요.
  • 여러 개의 IMEI 지원 추가됨
  • Android 14부터는 가속 암호화 명령을 지원하는 기기에서 파일 이름 암호화를 위해 AES-HCTR2가 선호됩니다.
  • 모바일 데이터 연결
  • Android 안전 센터에 관한 도움말 추가됨
  • 앱이 Android 14를 타겟팅하고 동적 코드 로드(DCL)를 사용하는 경우 동적으로 로드된 모든 파일은 읽기 전용으로 표시해야 합니다. 그러지 않으면 시스템에서 예외가 발생합니다. 가능하면 항상 코드를 동적으로 로드하지 않는 것이 좋습니다. 이렇게 하면 코드 삽입이나 코드 조작으로 인해 앱이 손상될 위험이 크게 증가하기 때문입니다.

전체 AOSP 출시 노트와 Android 개발자 기능 및 변경사항 목록을 확인하세요.

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 app 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 apps 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 App 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 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 types might 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

모든 Android 버전에는 사용자를 보호하기 위한 수십 가지 보안 향상 기능이 포함되어 있습니다. Android 11에서 사용할 수 있는 주요 보안 기능 개선사항은 Android 출시 노트를 참고하세요.

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

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.

Android 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.

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

모든 Android 버전에는 사용자를 보호하기 위한 수십 가지 보안 향상 기능이 포함되어 있습니다. 다음은 Android 6.0에서 사용할 수 있는 주요 보안 향상 기능 중 일부입니다.

  • 런타임 권한. 앱은 앱 설치 시 권한을 받는 대신 런타임 시에 권한을 요청합니다. 사용자는 M 앱과 M 이전 앱 모두에서 권한 설정과 해제를 전환할 수 있습니다.
  • 자체 검사 부팅. 휴대전화가 부트로더에서 운영체제에 이르기까지 정상적으로 작동하는지 확인하기 위해 실행 전에 진행하는 일련의 시스템 소프트웨어의 암호화 검사입니다.
  • 하드웨어 격리 보안. Fingerprint API, 잠금 화면, 기기 암호화, 클라이언트 인증서에서 사용되는 새로운 하드웨어 추상화 계층(HAL)은 커널 손상 또는 로컬의 물리적 공격으로부터 키를 보호합니다.
  • 지문. 이제 터치 한 번으로 기기를 잠금 해제할 수 있습니다. 또한 개발자는 지문을 사용하는 새로운 API를 활용하여 암호화 키를 잠그고 잠금 해제할 수 있습니다.
  • SD 카드 채택. 이동식 미디어는 여전히 블록 수준 암호화로 보호되면서 기기에 채택되고 앱 로컬 데이터, 사진, 동영상 등의 저장용량을 확장할 수 있습니다.
  • 텍스트 트래픽 삭제. 개발자는 새로운 StrictMode를 사용하여 앱이 일반 텍스트를 사용하지 않도록 할 수 있습니다.
  • 시스템 강화. SELinux에서 시행하는 정책을 통해 시스템을 강화합니다. 이를 통해 사용자 간의 격리, IOCTL 필터링, 노출된 서비스의 위협 감소, SELinux 도메인의 더 긴밀한 연결, 매우 제한된 /proc 액세스를 제공합니다.
  • USB 액세스 제어. 파일, 저장소 또는 휴대전화의 다른 기능에 USB 액세스를 허용하려면 사용자가 확인해야 합니다. 이제 사용자의 명시적 승인이 필요한 저장소에 액세스하면 기본적으로 충전만 허용됩니다.

Android 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 (through NFC, Bluetooth) or being used by someone with a trusted face.
  • Multi user, restricted profile, and guest modes for phones and 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 allows 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 및 이전 버전

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 apps. 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 apps or affect system behavior.
  • No setuid or setgid programs. Added support for filesystem capabilities to Android system files and removed all setuid or setgid programs. This reduces root attack surface and the likelihood of potential security vulnerabilities.
  • ADB authentication. Starting in 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 apps 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 apps. This prevents Android apps and apps launched from the shell from acquiring privileged capabilities.
  • AndroidKeyStore Provider. Android now has a keystore provider that allows apps to create exclusive use keys. This provides apps with an API to create or store private keys that cannot be used by other apps.
  • KeyChain isBoundKeyAlgorithm. Keychain API now provides a method (isBoundKeyType) that allows apps 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 can't 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 app code. This prevents Android apps from performing operations that can elevate privileges through 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 or 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.

Android는 Android 보안 개요에 설명된 다중 레이어 보안 모델을 제공합니다. 각 Android 업데이트에는 사용자를 보호하기 위한 수십 가지의 보안 향상 기능이 포함되어 있습니다. 다음은 Android 4.2에 도입된 보안 향상 기능 중 일부입니다.

  • 앱 인증: 사용자는 설치 전에 앱 인증을 사용 설정하고 앱 인증 도구에서 앱을 검사하도록 선택할 수 있습니다. 사용자가 유해할 수 있는 앱을 설치하려고 하면 앱 인증을 통해 사용자에게 이를 알릴 수 있습니다. 매우 불량한 앱이라면 설치를 차단할 수 있습니다.
  • 프리미엄 SMS를 더 효과적으로 제어: 앱에서 추가 요금이 발생할 수 있는 프리미엄 서비스를 사용하는 짧은 코드로 SMS를 보내려고 하면 Android에서 알림을 제공합니다. 사용자는 앱이 메시지를 보내도록 허용할지 또는 차단할지 선택할 수 있습니다.
  • 연결 유지 VPN: VPN 연결이 설정될 때까지 앱이 네트워크에 액세스하지 못하도록 VPN을 구성할 수 있습니다. 이렇게 하면 앱이 다른 네트워크를 통해 데이터를 전송할 수 없습니다.
  • 인증서 고정: 이제 Android 핵심 라이브러리에서 인증서 고정을 지원합니다. 인증서가 예상 인증서 모음에 연결되지 않으면 고정된 도메인에서 인증서 검증 실패 메시지를 수신합니다. 이를 통해 인증 기관의 손실 가능성을 방지합니다.
  • Android 권한 표시 개선: 사용자가 더 쉽게 이해할 수 있는 그룹으로 권한이 구성되었습니다. 권한을 검토하는 동안 사용자는 권한을 클릭하여 권한에 관한 자세한 정보를 볼 수 있습니다.
  • installd 강화: installd 데몬은 루트 사용자로 실행되지 않으므로 루트 권한 에스컬레이션의 잠재적인 공격 노출 영역이 줄어듭니다.
  • init 스크립트 강화: 이제 init 스크립트는 O_NOFOLLOW 의미 체계를 적용하여 심볼릭 링크 관련 공격을 방지합니다.
  • FORTIFY_SOURCE: 이제 Android에서 FORTIFY_SOURCE를 구현합니다. 이는 시스템 라이브러리와 앱에서 사용하여 메모리 손상을 방지합니다.
  • ContentProvider 기본 구성: API 수준 17을 타겟팅하는 앱은 각 콘텐츠 제공자에 대해 기본적으로 export를 false로 설정하여 앱의 기본 공격 노출 영역을 줄입니다.
  • 암호화: OpenSSL을 사용하도록 SecureRandom 및 Cipher.RSA의 기본 구현을 수정했습니다. OpenSSL 1.0.1을 사용하여 TLSv1.1 및 TLSv1.2에 SSL Socket 지원을 추가했습니다.
  • 보안 수정사항: 보안 수정사항이 적용되어 업그레이드된 오픈소스 라이브러리에는 WebKit, libpng, OpenSSL, LibXML이 포함됩니다. Android 4.2에는 Android 관련 취약점에 관한 수정사항도 포함되어 있습니다. 이러한 취약점 관련 정보는 Open Handset Alliance 멤버에게 제공되었으며 Android 오픈소스 프로젝트에서 수정사항을 사용할 수 있습니다. 보안을 개선하기 위해 이전 버전의 Android가 설치된 일부 기기에도 이러한 수정사항이 포함될 수 있습니다.

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)