CVE-2024-42133 in Linux
Summary
by MITRE • 07/30/2024
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Ignore too large handle values in BIG
hci_le_big_sync_established_evt is necessary to filter out cases where the handle value is belonging to ida id range, otherwise ida will be erroneously released in hci_conn_cleanup.
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability CVE-2024-42133 addresses a critical issue within the Linux kernel's Bluetooth subsystem that could lead to improper resource management and potential system instability. This flaw specifically affects the Bluetooth low energy (BLE) implementation where the kernel processes Big (Broadcast Information Group) synchronization events. The vulnerability stems from insufficient validation of handle values during the BIG synchronization establishment process, creating a scenario where malformed or excessively large handle identifiers could cause unexpected behavior in the kernel's connection management system.
The technical root cause of this vulnerability lies in the hci_le_big_sync_established_evt function which fails to properly validate handle values before processing them. When a handle value exceeds the expected range or belongs to an ida (integer descriptor allocator) id range, the system does not appropriately filter these cases. This omission results in the ida being erroneously released during hci_conn_cleanup operations, which can lead to memory corruption and resource management failures. The issue represents a classic case of inadequate input validation and boundary checking, where the kernel's Bluetooth implementation does not properly sanitize external inputs before processing them within critical system functions.
From an operational perspective, this vulnerability could enable attackers to potentially cause denial of service conditions or system instability through carefully crafted Bluetooth communications. The impact extends beyond simple service disruption as improper resource cleanup could lead to memory leaks, system crashes, or even potential privilege escalation scenarios depending on the system configuration. The vulnerability affects systems running Linux kernels that implement Bluetooth functionality, particularly those utilizing the HCI (Host Controller Interface) subsystem for Bluetooth operations. The risk is elevated in environments where Bluetooth devices are frequently connected and disconnected, or where automated Bluetooth management is employed.
The mitigation strategy for CVE-2024-42133 involves applying the official kernel patch that implements proper handle value validation within the hci_le_big_sync_established_evt function. This patch ensures that handle values are properly filtered to exclude those that belong to the ida id range before proceeding with connection cleanup operations. System administrators should prioritize updating their kernel versions to include this fix, particularly in environments where Bluetooth functionality is actively used or where the system may be exposed to untrusted Bluetooth devices. The fix aligns with CWE-129 Input Validation and CWE-764 Multiple Locks and Unlock Operations, addressing both improper input validation and resource management issues. Organizations should also consider implementing monitoring for anomalous Bluetooth connection patterns that might indicate exploitation attempts, as this vulnerability could potentially be leveraged in broader attack scenarios targeting embedded systems or IoT devices that rely on Linux kernel Bluetooth implementations.