CVE-2020-0449 in Android
Summary
by MITRE • 11/10/2020
In btm_sec_disconnected of btm_sec.cc, there is a possible memory corruption due to a use after free. This could lead to remote code execution in the Bluetooth server with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-9 Android-10 Android-11 Android-8.0 Android-8.1Android ID: A-162497143
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Analysis
by VulDB Data Team • 12/04/2020
The vulnerability identified as CVE-2020-0449 resides within the Bluetooth security implementation of Android operating systems, specifically in the btm_sec_disconnected function located in the btm_sec.cc source file. This memory corruption flaw represents a critical security weakness that could potentially enable remote code execution on affected devices. The vulnerability manifests as a use after free condition, where memory that has been deallocated is still being accessed or referenced by the system, creating opportunities for malicious code to exploit the memory state and gain unauthorized control over the Bluetooth subsystem.
The technical nature of this vulnerability places it under CWE-416, which specifically addresses use after free conditions in software development. This flaw occurs when the Bluetooth security module fails to properly manage memory allocation and deallocation processes during the disconnection sequence of Bluetooth security operations. When a Bluetooth connection is terminated, the system should properly release all associated memory resources and invalidate any references to those resources. However, in this case, the btm_sec_disconnected function does not adequately handle the memory cleanup process, leaving dangling pointers that can be exploited by attackers.
The operational impact of CVE-2020-0449 extends across multiple Android versions including Android 8.0, 8.1, 9, 10, and 11, affecting a substantial portion of the Android ecosystem. The vulnerability requires no additional execution privileges for exploitation, making it particularly dangerous as it can be triggered by remote attackers without requiring physical access or elevated user permissions. The need for user interaction to initiate exploitation suggests that the attack vector likely involves some form of Bluetooth connection establishment or data transmission that triggers the vulnerable code path. This characteristic makes the vulnerability more accessible in real-world scenarios where users frequently interact with Bluetooth-enabled devices and services.
From an attack perspective, this vulnerability aligns with ATT&CK technique T1059.007 for remote code execution through Bluetooth protocols. The memory corruption can potentially be leveraged to overwrite critical system memory locations, execute arbitrary code, or manipulate the Bluetooth server process to gain unauthorized access to device resources. The implications are severe as Bluetooth servers typically operate with significant system privileges and control over wireless communication channels, providing attackers with potential access to network interfaces, device configuration, and sensitive data transmission capabilities. The use after free condition creates opportunities for attackers to inject malicious code into the memory space or redirect execution flow through controlled memory corruption.
Mitigation strategies for CVE-2020-0449 should prioritize immediate system updates and patches provided by Google and device manufacturers, as this vulnerability has been addressed through official security releases. Organizations and users should implement Bluetooth connection monitoring and disable unnecessary Bluetooth services when not in use. Network administrators should consider implementing Bluetooth access controls and monitoring for suspicious connection patterns. The vulnerability highlights the importance of proper memory management practices in security-critical code and underscores the need for comprehensive code reviews and security testing of Bluetooth stack implementations. Additionally, implementing network segmentation and wireless access controls can help limit the potential impact of such vulnerabilities in enterprise environments where Bluetooth-enabled devices may be exposed to untrusted networks or users.