CVE-2019-2115 in Android
Summary
by MITRE
In GateKeeper::MintAuthToken of gatekeeper.cpp in Android 7.1.1, 7.1.2, 8.0, 8.1 and 9, there is possible memory corruption due to a double free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/13/2023
The vulnerability identified as CVE-2019-2115 represents a critical memory corruption flaw within the Android GateKeeper implementation, specifically affecting versions 7.1.1 through 9.0. This issue resides in the GateKeeper::MintAuthToken function within the gatekeeper.cpp source file, which serves as a crucial component in Android's biometric authentication framework. The vulnerability manifests as a double free condition that occurs when the system attempts to release memory that has already been deallocated, creating a scenario where the heap management structures become corrupted and potentially exploitable.
The technical nature of this vulnerability stems from improper memory management within the authentication token generation process. When GateKeeper::MintAuthToken processes authentication requests, it handles memory allocation and deallocation for token structures that are subsequently used for biometric verification. The double free condition occurs when the same memory block is freed twice during the execution flow, leading to heap corruption that can be leveraged by malicious actors. This flaw operates at the system level within the Android framework, specifically targeting the GateKeeper service that manages fingerprint and other biometric authentication data. The vulnerability is particularly concerning because it requires only system execution privileges to exploit, meaning an attacker with access to the system can potentially escalate their privileges to the highest level possible within the Android operating system.
The operational impact of CVE-2019-2115 extends beyond simple privilege escalation, as it directly compromises the integrity of Android's biometric authentication system. This vulnerability creates a pathway for attackers to bypass security measures that are designed to protect sensitive user data and system access. The double free condition can potentially be exploited to execute arbitrary code with system-level privileges, effectively allowing unauthorized access to all protected system resources and user data. The implications are particularly severe given that biometric authentication is a core security feature in modern Android devices, and compromising this system undermines the fundamental security model that users rely upon for device protection. Attackers can exploit this vulnerability without requiring user interaction, making it especially dangerous as it can be triggered automatically during normal authentication processes.
Security mitigations for CVE-2019-2115 primarily involve applying the official Android security patches released by Google, which address the memory management flaw in the GateKeeper implementation. Organizations and individuals should ensure their Android devices are updated to versions that include the patched gatekeeper.cpp implementation, specifically targeting Android 7.1.2, 8.0, 8.1, and 9.0 releases. Additionally, system administrators should implement comprehensive monitoring of authentication processes and consider temporary security measures such as disabling biometric authentication until proper patches are deployed. The vulnerability aligns with CWE-415, which describes improper double-free conditions in memory management, and represents a significant concern in the context of the ATT&CK framework's privilege escalation techniques. Organizations should also consider implementing additional security controls such as runtime application protection and memory integrity checking to detect and prevent exploitation attempts. Regular security audits of authentication systems and vulnerability assessments should be conducted to identify similar memory corruption issues that could present similar risks to system security.