CVE-2024-47671 in Linux
Summary
by MITRE • 10/09/2024
In the Linux kernel, the following vulnerability has been resolved:
USB: usbtmc: prevent kernel-usb-infoleak
The syzbot reported a kernel-usb-infoleak in usbtmc_write, we need to clear the structure before filling fields.
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Analysis
by VulDB Data Team • 03/21/2026
The vulnerability identified as CVE-2024-47671 affects the Linux kernel's USB Test and Measurement Class driver implementation, specifically within the usbtmc_write function. This issue represents a critical information disclosure flaw that could potentially expose sensitive kernel memory contents to unprivileged userspace applications. The vulnerability was discovered through automated fuzzing operations conducted by syzbot, a sophisticated kernel fuzzer that has become instrumental in identifying security issues within the Linux kernel ecosystem. The usbtmc driver is responsible for handling USB communication with test and measurement devices, commonly used in laboratory and industrial environments where precise instrumentation control is required.
The technical root cause of this vulnerability stems from improper memory initialization within the usbtmc_write function where kernel data structures are populated without first clearing the memory contents. This creates a scenario where uninitialized memory regions retain data from previous operations, potentially exposing kernel stack contents, heap data, or other sensitive information that was previously stored in those memory locations. The flaw specifically occurs during the processing of USB Test and Measurement Class write operations, where the driver fails to properly initialize the structure before populating its fields. This memory management oversight allows for potential information leakage that could reveal kernel memory layout details, cryptographic keys, or other confidential data that should remain protected within kernel space.
The operational impact of this vulnerability extends beyond simple information disclosure, as it could enable attackers to gain insights into kernel memory organization and potentially facilitate more sophisticated attacks. An attacker with access to a system running the affected kernel version could leverage this information leak to perform kernel address space layout randomization (ASLR) bypass techniques, making it easier to predict kernel memory locations for exploitation. This vulnerability aligns with CWE-248, which addresses "Uncaught Exception" in software systems, and represents a specific instance of improper initialization that could lead to information disclosure. The attack surface is particularly concerning in environments where USB Test and Measurement devices are frequently connected, as these systems may be accessible to users without elevated privileges. The vulnerability demonstrates how seemingly minor memory management oversights can create significant security implications in kernel-level code.
Mitigation strategies for CVE-2024-47671 should prioritize the immediate application of kernel updates from the vendor, as this vulnerability has been addressed in recent kernel releases. System administrators should ensure that all Linux systems running affected kernel versions are updated to the latest stable releases that contain the fix for this information leak. The fix typically involves adding proper memory clearing operations before structure population within the usbtmc_write function, ensuring that all memory regions are properly initialized before data is written to them. Organizations should also implement monitoring for unusual USB device connections and access patterns that might indicate exploitation attempts. Security teams should consider implementing kernel hardening measures such as stack canaries, kernel address space layout randomization, and other protections that can limit the impact of information disclosure vulnerabilities. This vulnerability serves as a reminder of the importance of proper memory initialization practices in kernel code and highlights the critical need for comprehensive testing and validation of kernel drivers before deployment in production environments.