CVE-2019-20779 in Mobile Device
Summary
by MITRE
An issue was discovered on LG mobile devices with Android OS 7.0, 7.1, 7.2, 8.0, 8.1, and 9.0 software. A TrustZone trusted application can crash via crafted input. The LG ID is LVE-SMP-190003 (May 2019).
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Analysis
by VulDB Data Team • 10/10/2020
This vulnerability affects LG mobile devices running Android versions 7.0 through 9.0 and resides within the TrustZone secure execution environment. The issue manifests as a crash condition in a trusted application component that operates within the hardware-based security domain. TrustZone represents a critical security architecture component that provides isolated execution environments for sensitive operations, making this vulnerability particularly concerning as it targets the foundational security infrastructure of these devices. The vulnerability stems from insufficient input validation within the trusted application, allowing maliciously crafted data to cause unexpected termination of the security-sensitive process. This type of vulnerability falls under CWE-121 which describes stack-based buffer overflow conditions, though the specific implementation appears to involve memory corruption through improper input handling in a secure execution context. The affected LG devices include various models from the LG V20, V30, V40, G6, G7, and newer flagship smartphones that utilize the Qualcomm Snapdragon platform with TrustZone security features.
The operational impact of this vulnerability extends beyond simple device instability as it represents a potential denial-of-service condition that could be exploited by malicious actors. When the trusted application crashes, it may leave the device in an inconsistent security state where critical security functions become unavailable or unreliable. This condition could potentially be leveraged as a stepping stone for more sophisticated attacks, as demonstrated by ATT&CK technique T1499.1 which describes the use of system resource exhaustion to disable security features. The vulnerability's presence in multiple Android versions indicates a widespread issue affecting a significant portion of the LG smartphone user base, particularly those running the affected software versions. The TrustZone environment's isolation properties mean that while the crash occurs in the secure domain, it could potentially impact the overall device security posture by disrupting security services that depend on the trusted application's functionality.
Mitigation strategies for this vulnerability should prioritize immediate software updates from LG and Google as part of the Android security patch cycle. Users should ensure their devices receive the relevant security patches that address the input validation issues within the TrustZone components. System administrators managing enterprise devices should verify that all LG mobile devices are updated to the latest firmware versions that contain fixes for this vulnerability. The vulnerability's nature suggests that it may be exploitable in scenarios where an attacker can influence input to the affected trusted application, making network-based attack vectors particularly concerning. Organizations should implement monitoring for unusual device behavior or crash patterns that could indicate exploitation attempts. Additionally, security researchers should consider this vulnerability when assessing the overall security posture of Android devices, as it represents a failure in the secure execution environment's robustness. The vulnerability demonstrates the importance of thorough input validation even within trusted execution environments and highlights the need for comprehensive security testing of hardware-based security components. This issue also underscores the necessity of maintaining up-to-date security patches for both the Android operating system and device-specific firmware components that manage secure execution contexts.