CVE-2019-9468 in Android
Summary
by MITRE
In export_key_der of export_key.cpp, there is possible memory corruption due to a double free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android Versions: Android-10 Android ID: A-139683471
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Analysis
by VulDB Data Team • 01/07/2020
The vulnerability identified as CVE-2019-9468 represents a critical memory corruption issue within the Android operating system's cryptographic key export functionality. This flaw exists in the export_key_der function located within the export_key.cpp source file, where a double free condition can occur during the key export process. The vulnerability specifically affects Android 10 and is tracked under Android ID A-139683471, demonstrating the severity and scope of the issue within the Android ecosystem. The double free vulnerability arises when the same memory block is freed twice, potentially leading to memory corruption that can be exploited by malicious actors.
The technical implementation of this vulnerability stems from improper memory management within the cryptographic key export mechanism. When the export_key_der function processes key data for export in DER format, it fails to properly track memory allocations and deallocations, creating conditions where memory blocks can be freed multiple times. This memory corruption scenario can result in unpredictable behavior, including potential code execution or privilege escalation. The vulnerability's classification aligns with CWE-415, which specifically addresses double free conditions in memory management, and represents a classic example of improper resource management that can lead to arbitrary code execution.
From an operational perspective, this vulnerability presents a significant risk as it enables local privilege escalation without requiring any additional execution privileges or user interaction. The exploitability factor is particularly concerning because it can be leveraged by malicious applications already running on the device to gain elevated privileges, potentially allowing access to protected system resources and data. The lack of user interaction requirements means that an attacker could exploit this vulnerability silently in the background, making detection and prevention more challenging. This characteristic places the vulnerability in the ATT&CK matrix under privilege escalation techniques, specifically targeting local system access and persistence mechanisms.
The mitigation strategies for CVE-2019-9468 should focus on immediate patch deployment through Android security updates, which typically address the underlying memory management issues in the export_key.cpp implementation. System administrators and device manufacturers should prioritize the application of security patches to prevent exploitation. Additionally, implementing runtime monitoring for memory corruption patterns and establishing proper memory allocation tracking can help detect potential exploitation attempts. Organizations should also consider applying additional security controls such as application sandboxing and privilege separation to limit the potential impact of successful exploitation attempts. The vulnerability highlights the critical importance of proper memory management in cryptographic implementations and underscores the need for comprehensive code review processes to identify and remediate similar issues in security-critical components.