CVE-2023-21395 in Android
Summary
by MITRE • 10/30/2023
In Bluetooth, there is a possible out of bounds read due to a use after free. This could lead to remote information disclosure over Bluetooth 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
The vulnerability identified as CVE-2023-21395 represents a critical security flaw within Bluetooth protocol implementations that manifests as an out-of-bounds read condition stemming from a use-after-free error. This type of vulnerability occurs when a program continues to reference memory that has already been freed, creating opportunities for malicious actors to access unauthorized data through carefully crafted Bluetooth communications. The flaw exists at the protocol level where Bluetooth implementations fail to properly validate memory access patterns during routine operations, particularly when handling specific data structures related to connection management and packet processing.
The technical nature of this vulnerability places it squarely within CWE-416, which catalogs use-after-free conditions as a fundamental memory safety issue that can result in information disclosure, arbitrary code execution, or system instability. The vulnerability's remote exploitation capability means that attackers can trigger the condition without requiring physical proximity or user interaction, making it particularly dangerous in environments where Bluetooth devices are frequently connected to untrusted networks or systems. The use-after-free pattern creates a scenario where freed memory blocks may contain sensitive information that persists in memory until overwritten, allowing an attacker to extract potentially confidential data through carefully constructed Bluetooth traffic.
From an operational perspective, the impact of CVE-2023-21395 extends beyond simple information disclosure to potentially compromise the integrity of Bluetooth communications and device security. The vulnerability affects devices that implement Bluetooth protocols, including smartphones, laptops, IoT devices, and automotive systems, where unauthorized information extraction could lead to exposure of authentication tokens, connection parameters, or other sensitive operational data. This risk is amplified by the fact that the attack requires no additional privileges or user interaction, making it an attractive target for automated exploitation campaigns. The vulnerability's presence in core Bluetooth implementations means that widespread device compromise is possible, particularly in environments where Bluetooth connectivity is frequently utilized and security controls are minimal.
The exploitation of this vulnerability aligns with tactics documented in the ATT&CK framework under T1046, where adversaries leverage network services to gain information about target systems. The remote nature of exploitation places this vulnerability in the category of network-based attacks that can be executed from any location where Bluetooth connectivity is possible, potentially enabling attackers to gather intelligence about device configurations, connection history, or other operational details. Organizations should implement immediate mitigations including firmware updates, Bluetooth protocol hardening measures, and network segmentation to prevent unauthorized access. The vulnerability also highlights the importance of memory safety practices in protocol implementations and underscores the need for comprehensive security testing of network communication stacks to prevent similar use-after-free conditions from emerging in other Bluetooth-related components.
Security practitioners should prioritize patch management for affected Bluetooth implementations and consider implementing Bluetooth traffic monitoring to detect potential exploitation attempts. The vulnerability demonstrates how seemingly minor memory management errors can create significant security risks in widely deployed protocols, emphasizing the critical importance of robust code review processes and memory safety validation in network protocol implementations.