CVE-2019-2007 in Android
Summary
by MITRE
In getReadIndex and getWriteIndex of FifoControllerBase.cpp, there is a possible out-of-bounds write due to an integer overflow. This could lead to local escalation of privilege in the audio server with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.1 Android-9Android ID: A-120789744
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Analysis
by VulDB Data Team • 10/07/2023
The vulnerability identified as CVE-2019-2007 resides within the audio server component of Android systems, specifically affecting versions 8.1 and 9. This issue manifests in the FifoControllerBase.cpp file where the getReadIndex and getWriteIndex functions fail to properly validate integer values, creating a condition that allows for integer overflow. The flaw occurs when the system processes audio data through FIFO (First In, First Out) buffers, which are fundamental components in audio processing pipelines. The integer overflow condition arises when calculations involving buffer indices exceed the maximum representable value for the integer type used, causing the index to wrap around to a much smaller value. This overflow behavior creates a scenario where memory access operations can reference locations outside the intended buffer boundaries, potentially allowing malicious code to write data beyond the allocated memory space.
The security implications of this vulnerability are significant as it enables local privilege escalation within the audio server context. Attackers can exploit this weakness to gain elevated privileges without requiring additional execution privileges or user interaction, making the attack vector particularly dangerous. The vulnerability operates at the kernel level within the audio subsystem, which typically runs with high privileges, providing a direct pathway for privilege elevation. When the integer overflow occurs during buffer index calculations, it can cause the audio server to write data to memory locations that it should not have access to, potentially allowing for code execution or memory corruption that could be leveraged to escalate privileges. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow conditions that can lead to memory corruption and privilege escalation attacks.
The operational impact of CVE-2019-2007 extends beyond simple privilege escalation as it represents a critical weakness in Android's audio processing architecture. The vulnerability affects systems where audio services are running with elevated privileges, creating a persistent threat vector that could be exploited by malicious applications or processes. The lack of user interaction requirement makes this vulnerability particularly concerning because it can be exploited automatically without any user awareness or consent. The attack surface is limited to systems running the affected Android versions, but given the widespread adoption of these versions, the potential impact is substantial. The vulnerability's exploitation can result in complete compromise of the audio server process, potentially leading to broader system compromise if additional vulnerabilities exist within the audio subsystem or related components.
Mitigation strategies for CVE-2019-2007 should focus on addressing the integer overflow condition through proper input validation and boundary checking mechanisms. The most effective approach involves implementing bounds checking in the getReadIndex and getWriteIndex functions to prevent integer overflow conditions from occurring. This includes validating that calculated buffer indices remain within the valid range before performing any memory operations. Security patches should include proper integer overflow protection mechanisms that ensure index calculations cannot exceed maximum allowable values. Additionally, developers should implement defensive programming practices such as using safe integer arithmetic operations and employing compiler-level protections against integer overflows. The mitigation efforts should align with ATT&CK framework tactics that address privilege escalation and defense evasion, as this vulnerability can be used to maintain persistent access to systems. Regular security updates and patch management processes should be prioritized to ensure that affected Android versions receive timely fixes that address the underlying integer overflow conditions in the audio subsystem components.