CVE-2017-16529 in Linux
Summary
by MITRE
The snd_usb_create_streams function in sound/usb/card.c in the Linux kernel before 4.13.6 allows local users to cause a denial of service (out-of-bounds read and system crash) or possibly have unspecified other impact via crafted system calls.
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Analysis
by VulDB Data Team • 01/06/2023
The vulnerability identified as CVE-2017-16529 represents a critical out-of-bounds read flaw within the Linux kernel's USB audio subsystem, specifically affecting the snd_usb_create_streams function in sound/usb/card.c. This issue exists in kernel versions prior to 4.13.6 and provides local attackers with the capability to trigger system crashes or potentially execute arbitrary code through carefully crafted system calls. The vulnerability stems from inadequate input validation and bounds checking within the USB audio device initialization process, where the kernel fails to properly validate user-supplied parameters during USB audio stream creation operations.
The technical exploitation of this vulnerability occurs when a local user executes crafted system calls that manipulate the parameters passed to the snd_usb_create_streams function. The flaw manifests as an out-of-bounds memory read operation that can lead to kernel memory corruption and subsequent system crashes. This type of vulnerability falls under CWE-129, which addresses improper validation of array indices, and specifically aligns with the ATT&CK technique T1068 for locally executed malicious code. The kernel's USB audio subsystem processes audio data streams from USB devices, and during the stream creation phase, the function does not adequately validate the size or content of incoming data structures, creating a pathway for attackers to access memory locations outside the intended bounds.
From an operational impact perspective, this vulnerability presents significant risks to systems running affected kernel versions, particularly those with USB audio devices installed or those that might be exploited as part of a broader attack chain. The denial of service aspect can result in complete system crashes, forcing administrators to reboot affected systems and potentially disrupting critical services. The unspecified other impacts could include privilege escalation or information disclosure, depending on the specific memory locations accessed during the out-of-bounds read. Systems that rely heavily on audio processing or USB audio devices are particularly vulnerable, as the attack surface expands to include any application or process that might interact with USB audio subsystems through system calls.
Mitigation strategies for CVE-2017-16529 primarily focus on kernel version updates to 4.13.6 or later, which contain the necessary patches to address the bounds checking deficiencies in the snd_usb_create_streams function. System administrators should prioritize patching affected systems, particularly those running kernel versions between 2.6.39 and 4.13.5. Additionally, implementing proper access controls and limiting local user privileges can reduce the attack surface, though this does not eliminate the vulnerability itself. The patch addresses the core issue by introducing proper input validation and bounds checking mechanisms that prevent the out-of-bounds memory access from occurring during USB audio stream creation operations. Organizations should also consider monitoring for suspicious system call patterns and implementing intrusion detection systems to identify potential exploitation attempts targeting this vulnerability.