CVE-2023-21392 in Android
Summary
by MITRE • 10/30/2023
In Bluetooth, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege when connecting to a Bluetooth device with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/22/2023
This vulnerability exists within the Bluetooth subsystem of affected operating systems and represents a critical use after free condition that can be exploited for local privilege escalation. The flaw occurs when the Bluetooth stack improperly handles memory management during device connection processes, specifically when freeing memory resources that are subsequently accessed by malicious code. This type of vulnerability falls under the Common Weakness Enumeration category CWE-416 which defines use after free conditions as a serious memory safety issue where program code continues to reference memory after it has been freed. The vulnerability is particularly dangerous because it requires no user interaction or additional privileges to exploit, making it an ideal candidate for automated attacks within local network environments.
The technical implementation of this flaw involves the Bluetooth protocol stack maintaining references to memory structures that are freed during normal connection handling procedures. When a malicious Bluetooth device connects to a vulnerable system, the connection process triggers a sequence where memory is freed but not properly invalidated, allowing subsequent operations to access this freed memory region. This memory corruption can be leveraged by an attacker to execute arbitrary code with elevated privileges, potentially gaining system-level control over the affected device. The exploitation mechanism operates at the kernel level within the Bluetooth subsystem, making the attack surface particularly severe as it can bypass standard user permission checks and privilege boundaries.
The operational impact of CVE-2023-21392 extends beyond simple privilege escalation, as it represents a significant security weakness that can be exploited by attackers within Bluetooth range of vulnerable devices. This vulnerability aligns with ATT&CK technique T1068 which describes local privilege escalation through kernel exploits, and specifically demonstrates how Bluetooth protocols can serve as attack vectors for system compromise. The lack of user interaction requirements makes this vulnerability particularly concerning for mobile devices, IoT systems, and any environment where Bluetooth connectivity is enabled by default. Attackers can potentially exploit this vulnerability in environments such as corporate networks, public spaces, or even within the home, where Bluetooth devices are frequently paired and connected without user awareness or explicit permission.
Mitigation strategies for this vulnerability should focus on immediate patch deployment and system hardening measures. Organizations should prioritize updating all affected systems to the latest Bluetooth stack implementations that address the use after free condition. Network administrators should consider disabling Bluetooth functionality on systems where it is not required, particularly in high-security environments. The implementation of Bluetooth device whitelisting and connection monitoring can provide additional layers of defense. Security teams should also monitor for unusual Bluetooth connection patterns and implement endpoint detection and response solutions that can identify potential exploitation attempts. Additionally, regular security assessments should be conducted to ensure that Bluetooth subsystems are properly configured and that all available security patches have been applied. System administrators should also consider implementing network segmentation to limit the potential impact of successful exploitation attempts and establish incident response procedures specifically for Bluetooth-based security incidents.