CVE-2019-9459 in Android
Summary
by MITRE
In libttspico, there is a possible OOB write due to a heap buffer overflow. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-79593569
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Analysis
by VulDB Data Team • 09/13/2020
The vulnerability CVE-2019-9459 represents a critical heap buffer overflow flaw within the libttspico library component of Android systems. This library serves as a text-to-speech engine responsible for converting textual content into audible speech output. The buffer overflow occurs when processing malformed input data, specifically within the heap memory management structures that handle speech synthesis operations. The flaw exists in how the library allocates and manages memory buffers during text processing, creating conditions where an attacker can write data beyond the allocated buffer boundaries.
The technical nature of this vulnerability places it under CWE-121, which categorizes heap-based buffer overflow conditions that can result in arbitrary code execution. This particular flaw demonstrates a classic out-of-bounds write scenario where insufficient bounds checking allows malicious input to overwrite adjacent memory locations. The vulnerability is particularly concerning because it operates within the system-level text-to-speech functionality that runs with elevated privileges, enabling potential privilege escalation without requiring any additional user interaction or execution privileges. The exploitation mechanism leverages the heap overflow to manipulate memory layout and potentially execute malicious code with system-level access.
The operational impact of CVE-2019-9459 extends beyond simple remote code execution as it provides a pathway for complete system compromise through privilege escalation. Since the vulnerability exists in the core Android text-to-speech functionality, any application that utilizes this library can potentially trigger the exploit. The attack vector requires no user interaction, making it particularly dangerous as it can be exploited silently in the background. This characteristic aligns with ATT&CK technique T1068, which describes local privilege escalation through exploitation of system vulnerabilities. The vulnerability affects Android 10 systems and represents a significant security gap that could allow attackers to gain unauthorized system access and potentially escalate privileges to root level.
Mitigation strategies for this vulnerability require immediate system updates and patches provided by Google as part of their regular security updates. Organizations should implement comprehensive monitoring for any suspicious text-to-speech related activities that might indicate exploitation attempts. The patch addresses the underlying heap buffer overflow by implementing proper bounds checking and memory management within the libttspico library. Additionally, system administrators should consider implementing application whitelisting policies that restrict access to potentially vulnerable text-to-speech functions. The vulnerability demonstrates the importance of proper memory management in system libraries and highlights the need for thorough security testing of core Android components. Regular security assessments and vulnerability scanning should include checks for similar buffer overflow conditions in other system libraries to prevent similar exploitation scenarios.