CVE-2019-15416 in keyaki_kddi
Summary
by MITRE
The Sony keyaki_kddi Android device with a build fingerprint of Sony/keyaki_kddi/keyaki_kddi:7.1.1/TONE3-3.0.0-KDDI-170517-0326/1:user/dev-keys contains a pre-installed app with a package name of com.kddi.android.packageinstaller app (versionCode=70008, versionName=08.10.03) that allows other pre-installed apps to perform app installation via an accessible app component. This capability can be accessed by any pre-installed app on the device which can obtain signatureOrSystem permissions that are required by other other pre-installed apps that exported their capabilities to other pre-installed app.
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Analysis
by VulDB Data Team • 02/20/2024
The vulnerability identified as CVE-2019-15416 resides within the Sony keyaki_kddi Android device running Android 7.1.1, specifically targeting a pre-installed application named com.kddi.android.packageinstaller. This application serves as a package installer component that has been improperly configured with excessive permissions, creating a significant security risk within the device's application ecosystem. The flaw manifests through the application's exported component design, which allows other pre-installed applications to invoke installation capabilities without proper authorization mechanisms. This vulnerability represents a critical flaw in Android's permission model and application isolation principles, as it enables arbitrary pre-installed applications to perform package installation operations through accessible app components. The device's build fingerprint Sony/keyaki_kddi/keyaki_kddi:7.1.1/TONE3-3.0.0-KDDI-170517-0326/1 indicates a specific KDDI carrier variant that inherits this security weakness from the underlying Android framework implementation.
The technical exploitation of this vulnerability stems from the improper configuration of the package installer application's exported components, which are accessible to other pre-installed applications on the device. The vulnerability occurs when pre-installed applications with signatureOrSystem permissions can access the exported installer capabilities, bypassing normal Android security controls that should prevent arbitrary package installation. This design flaw allows malicious or compromised pre-installed applications to silently install additional applications, potentially including malware or unauthorized system modifications. The vulnerability is classified as a permission escalation issue that violates the principle of least privilege, where the exported installer component lacks proper authentication or authorization checks before allowing installation operations to proceed. This weakness directly relates to CWE-284, which addresses improper access control, and specifically manifests as an improper privilege management scenario where legitimate system applications can be leveraged to perform unauthorized operations.
The operational impact of this vulnerability extends beyond simple application installation capabilities, as it creates a persistent attack vector that can be exploited by pre-installed applications to install malicious software without user consent or awareness. An attacker with access to a pre-installed application that can obtain signatureOrSystem permissions could potentially install backdoors, spyware, or other malicious applications that would operate with elevated privileges and system-level access. The vulnerability is particularly concerning because it operates within the system-level application space, making it difficult to detect and remediate through standard user-level security measures. This flaw can enable persistent threats that maintain system-level access and can potentially compromise the integrity of the entire device through the installation of unauthorized applications that may modify system components or establish covert communication channels.
Mitigation strategies for this vulnerability should focus on restricting access to the exported installer components and implementing proper access controls within the Android application framework. Device manufacturers should ensure that pre-installed applications do not export installer capabilities unless absolutely necessary, and when such exports are required, proper signature verification and permission checking mechanisms must be implemented. The recommended approach involves configuring the AndroidManifest.xml files to properly restrict component access through the use of android:permission attributes and ensuring that only applications with explicit authorization can access the installer components. Security teams should also consider implementing runtime monitoring of package installation activities and establishing proper application sandboxing controls to prevent unauthorized access to system installation capabilities. This vulnerability highlights the importance of following the principle of least privilege and proper application security hardening practices as outlined in the OWASP Mobile Top 10 and NIST Mobile Security Guidelines, where the improper exposure of system-level components creates significant security risks that can be exploited by malicious actors within the device's trusted application environment.