CVE-2019-9350 in Android
Summary
by MITRE
In Keymaster, there is a possible EoP due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-129562815
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9350 resides within the Keymaster implementation on Android devices, representing a critical privilege escalation flaw that allows attackers to gain elevated system privileges without requiring any additional execution privileges or user interaction. This issue specifically manifests as a use-after-free condition within the Keymaster cryptographic service, which is responsible for secure key storage and cryptographic operations on Android devices.
The technical flaw occurs when the Keymaster service handles cryptographic operations involving key material, creating a scenario where memory allocated to a key object is freed but subsequently accessed by other processes or threads within the same service. This use-after-free vulnerability stems from improper memory management within the cryptographic key handling routines, where the system fails to properly validate or track the lifecycle of key objects during concurrent operations. The vulnerability is particularly concerning because Keymaster operates at a privileged level within the Android security architecture, making it a critical component for maintaining system integrity and secure cryptographic operations.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with the ability to execute arbitrary code with system-level privileges, potentially enabling complete system compromise. The absence of user interaction requirements makes this vulnerability particularly dangerous, as it can be exploited silently in the background without any visible user prompts or warnings. Attackers could leverage this flaw to install malicious applications, modify system files, access sensitive user data, or establish persistent backdoors within the device. The vulnerability affects Android 10 and potentially earlier versions, indicating a widespread exposure across numerous devices and user bases.
Mitigation strategies for CVE-2019-9350 primarily involve applying the security patches released by Google as part of their Android security updates, specifically targeting the Keymaster implementation and related cryptographic services. Organizations should implement comprehensive patch management protocols to ensure timely deployment of these security updates across all affected devices. Additionally, system administrators should consider implementing monitoring solutions to detect anomalous behavior that might indicate exploitation attempts, particularly focusing on unauthorized access patterns to cryptographic services and unusual memory allocation activities. The vulnerability aligns with CWE-416, which describes the use-after-free error condition, and represents a significant concern within the ATT&CK framework under privilege escalation techniques, specifically targeting the use of system services and cryptographic components for unauthorized access. Organizations should also consider implementing device hardening measures and restricting access to sensitive system components to minimize the potential impact of such vulnerabilities.