CVE-2018-9484 in Android
Summary
by MITRE • 11/20/2024
In l2cu_send_peer_config_rej of l2c_utils.cc, there is a possible out of bounds read due to a missing bounds check. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2018-9484 resides within the Bluetooth stack implementation of the Linux kernel, specifically in the l2cu_send_peer_config_rej function located in the l2c_utils.cc source file. This flaw represents a classic out-of-bounds read condition that occurs when processing Bluetooth Low Energy connection parameters. The vulnerability stems from a missing bounds check that fails to validate the size of incoming configuration rejection messages before attempting to access memory locations. Such a condition allows an attacker to potentially read memory contents beyond the intended buffer boundaries, creating opportunities for information disclosure attacks.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of array indices, and more specifically with CWE-125, which addresses out-of-bounds read conditions. The flaw operates at the transport layer of the Bluetooth protocol stack, where the l2c_utils.cc module handles lower layer communication utilities for the Logical Link Control and Adaptation Protocol layer. When a peer device sends a configuration rejection message, the system does not properly validate the message length against expected parameters, allowing for memory access beyond allocated boundaries. This type of vulnerability falls under the ATT&CK technique T1059.001, which encompasses command and scripting interpreter usage, as exploitation may involve crafting malicious Bluetooth packets to trigger the condition.
The operational impact of CVE-2018-9484 is significant as it enables remote information disclosure without requiring any additional privileges or user interaction for exploitation. This characteristic makes it particularly dangerous in environments where Bluetooth devices are exposed to untrusted networks or adversaries. The vulnerability affects systems running Linux kernel versions that include the affected Bluetooth stack components, potentially exposing sensitive kernel memory contents including cryptographic keys, session information, or other confidential data stored in memory. The lack of user interaction requirement means that exploitation can occur passively, making it especially concerning for mobile devices, IoT systems, and other Bluetooth-enabled platforms that may be continuously exposed to potential attackers.
Mitigation strategies for this vulnerability include applying the appropriate kernel security patches released by the Linux kernel maintainers, which typically involve adding proper bounds checking to validate message lengths before memory access operations. Organizations should prioritize patching systems running affected kernel versions, particularly those handling Bluetooth communications in sensitive environments. Network administrators should also consider implementing Bluetooth access controls and monitoring for unusual Bluetooth traffic patterns that might indicate exploitation attempts. Additionally, system hardening measures such as disabling unnecessary Bluetooth services, implementing proper network segmentation, and conducting regular security assessments of Bluetooth-enabled devices can help reduce the attack surface. The vulnerability demonstrates the importance of proper input validation in kernel space code and highlights the critical need for thorough security testing of protocol implementations, particularly those handling network communication in operating system kernels.