CVE-2019-1993 in Android
Summary
by MITRE
In register_app of btif_hd.cc, there is a possible memory corruption due to an integer overflow. 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-8.0 Android-8.1 Android-9. Android ID: A-119819889.
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Analysis
by VulDB Data Team • 07/26/2023
The vulnerability identified as CVE-2019-1993 resides within the Bluetooth subsystem of Android operating systems, specifically in the register_app function located in the btif_hd.cc source file. This flaw represents a critical memory corruption issue that stems from an integer overflow condition, making it particularly dangerous for privilege escalation attacks. The vulnerability affects Android versions 8.0, 8.1, and 9.0, indicating a widespread impact across multiple generations of the Android platform. The integer overflow occurs during the registration process of Bluetooth applications, where improper handling of integer values can lead to memory corruption that compromises system integrity.
The technical nature of this vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions that can result in memory corruption and arbitrary code execution. The flaw operates at the Bluetooth Interface Transport layer, where the system processes Bluetooth application registrations. When an application attempts to register with the Bluetooth subsystem, the integer overflow in the register_app function can cause buffer overflows or memory corruption that allows malicious code to manipulate memory locations. This condition is particularly concerning because it requires no user interaction for exploitation and can be triggered through normal Bluetooth application registration processes. The vulnerability's design allows for local privilege escalation, meaning that an attacker with minimal privileges can leverage this flaw to gain elevated system-level access.
The operational impact of CVE-2019-1993 extends beyond simple memory corruption, as it enables local privilege escalation without requiring additional execution privileges or user interaction. This characteristic places the vulnerability in the ATT&CK framework under privilege escalation techniques, specifically targeting the 'Local Privilege Escalation' tactic. The attack vector is particularly insidious because it can be exploited through legitimate Bluetooth application registration processes, making it difficult to detect and prevent. Once exploited, the vulnerability allows attackers to execute arbitrary code with system-level privileges, potentially enabling full system compromise. The lack of user interaction requirements means that this vulnerability can be exploited automatically, making it particularly dangerous in environments where Bluetooth devices are frequently paired or where applications regularly register with the Bluetooth subsystem.
Mitigation strategies for CVE-2019-1993 should focus on immediate patching of affected Android versions, as Google released security updates addressing this specific integer overflow condition. Organizations should implement comprehensive mobile device management policies that ensure timely deployment of security patches across all Android devices. The vulnerability's nature suggests that input validation and proper integer boundary checking should be implemented in all Bluetooth-related subsystem functions. Additionally, security monitoring should include detection of unusual Bluetooth registration patterns that might indicate exploitation attempts. System administrators should also consider implementing network segmentation to limit Bluetooth communication where possible and disable unnecessary Bluetooth services on devices that do not require them. The vulnerability demonstrates the critical importance of proper integer handling in system-level code and serves as a reminder of the potential for memory corruption flaws to enable privilege escalation attacks in mobile operating systems.