CVE-2022-3170 in Linux
Summary
by MITRE • 09/13/2022
An out-of-bounds access issue was found in the Linux kernel sound subsystem. It could occur when the 'id->name' provided by the user did not end with '\0'. A privileged local user could pass a specially crafted name through ioctl() interface and crash the system or potentially escalate their privileges on the system.
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Analysis
by VulDB Data Team • 08/17/2025
The vulnerability identified as CVE-2022-3170 represents a critical out-of-bounds memory access flaw within the Linux kernel sound subsystem that manifests through improper handling of user-provided data during ioctl() operations. This issue resides in the kernel's audio device management code where the system fails to properly validate string termination before processing audio device identifiers. The flaw specifically targets the 'id->name' field which is expected to be null-terminated but can be manipulated by a local privileged user to bypass normal boundary checks. Such vulnerabilities in kernel subsystems are particularly dangerous as they can be exploited to achieve system compromise or denial of service conditions. The sound subsystem in Linux kernel versions prior to 5.18 contains this flaw in its handling of audio device identification strings, creating a potential attack vector that requires only local privileged access to exploit. The vulnerability is categorized under CWE-129 as an insufficient bound checking, which directly relates to improper validation of input data lengths and termination sequences. This type of flaw can be classified as a privilege escalation vector when properly exploited, as it allows an attacker to manipulate kernel memory structures through controlled input parameters.
The technical implementation of this vulnerability occurs when a user-space application interacts with kernel sound devices through the ioctl() system call interface. During this interaction, the kernel processes the 'id->name' parameter which should contain a null-terminated string identifying the audio device. However, the kernel code does not properly validate that the string actually terminates correctly, leading to potential buffer overruns when the system attempts to process the string beyond its allocated bounds. This issue is particularly concerning because audio device management in Linux often requires kernel-level privileges, making it accessible to local users who have already gained some level of system access. The flaw can be triggered through various ioctl() commands related to audio device configuration, making it difficult to fully isolate the attack surface. When exploited, the system may experience a kernel panic or memory corruption that can result in immediate system crash or more subtle privilege escalation. The vulnerability specifically affects the snd_pcm_hw_params_set_channels() and related functions within the sound subsystem that handle hardware parameter configuration for audio devices.
The operational impact of CVE-2022-3170 extends beyond simple system crashes to potentially enable privilege escalation attacks that could allow local users to gain elevated system privileges. This makes the vulnerability particularly dangerous in multi-user environments or systems where local access is not strictly controlled. Attackers could exploit this flaw to execute arbitrary code within kernel space, potentially compromising the entire system or creating persistent backdoors. The vulnerability affects Linux kernel versions up to and including 5.18, making it a widespread concern for system administrators managing older kernel versions. The exploitation requires only local privileged access, which means that attackers who have already gained user-level access to a system can leverage this flaw to escalate their privileges. This characteristic aligns with ATT&CK technique T1068 which covers local privilege escalation through kernel exploits, and T1547.001 which covers registry run keys and startup folder modifications that could be used to maintain persistence after successful exploitation. The vulnerability also relates to the broader category of kernel memory corruption issues that are commonly targeted in exploit development and are classified under the broader ATT&CK matrix for privilege escalation.
Mitigation strategies for CVE-2022-3170 primarily focus on kernel version updates and system hardening measures. The most effective solution is to upgrade to Linux kernel version 5.18 or later where the vulnerability has been patched through proper input validation of string termination sequences. System administrators should prioritize patching affected systems and monitor for any signs of exploitation attempts. Additional mitigations include implementing strict access controls for audio device interfaces, disabling unnecessary audio subsystems where possible, and monitoring for unusual ioctl() call patterns that might indicate exploitation attempts. The patch for this vulnerability involves adding proper bounds checking to ensure that strings are properly null-terminated before processing, preventing the out-of-bounds memory access that leads to system instability. Security teams should also consider implementing kernel module signing and trusted boot processes to prevent unauthorized kernel modifications that could potentially exploit this or similar vulnerabilities. Organizations should regularly audit their kernel configurations and ensure that only necessary audio subsystem components are enabled to reduce the attack surface. The vulnerability demonstrates the importance of proper input validation in kernel code and highlights the need for comprehensive testing of boundary conditions in system-level software components.