CVE-2022-48701 is a vulnerability identified in the Linux kernel's ALSA (Advanced Linux Sound Architecture) USB audio driver subsystem. Specifically, the flaw exists in the function __snd_usb_parse_audio_interface(), which is responsible for parsing USB audio interface descriptors. The vulnerability arises when a USB audio device with the USB vendor ID 0x04fa and product ID 0x4201 presents fewer than four interfaces. Under these conditions, the driver performs an out-of-bounds read while parsing the interface descriptors, due to insufficient validation of the number of interfaces before accessing them. This can lead to reading memory beyond the allocated bounds, potentially causing kernel crashes (denial of service) or exposing kernel memory contents. The root cause is a lack of proper boundary checks on the interface count before accessing the interface descriptors array. The issue has been addressed by adding a check on the number of interfaces to prevent out-of-bounds access. The vulnerability affects Linux kernel versions containing the specified commit hash (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2) and likely earlier versions before the patch. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. The vulnerability requires physical or logical access to the system to connect or emulate a malicious USB audio device with the specified USB ID and crafted interface descriptors. No authentication or user interaction beyond device connection is necessary. This vulnerability is a memory safety issue that could be leveraged for denial of service or potentially as a stepping stone for privilege escalation if combined with other vulnerabilities.

For European organizations, the impact of CVE-2022-48701 primarily concerns systems running Linux kernels with the vulnerable ALSA USB audio driver, especially those that allow USB device connections. The vulnerability could be exploited by an attacker with physical access or via social engineering to connect a malicious USB audio device, causing kernel crashes and denial of service. This could disrupt critical services, especially in environments relying on Linux-based infrastructure for audio processing, multimedia, or embedded systems. While direct remote exploitation is unlikely, organizations with shared workspaces, public access terminals, or supply chain exposure could be at risk. The out-of-bounds read might also leak kernel memory, potentially exposing sensitive information, although this is less certain without known exploit details. The vulnerability could affect industrial control systems, telecommunications equipment, or IoT devices running Linux with USB audio support, which are common in European manufacturing and technology sectors. The impact on confidentiality, integrity, and availability is moderate, with availability (denial of service) being the most likely consequence. The lack of known exploits reduces immediate risk but does not eliminate the need for timely patching.

European organizations should implement the following specific mitigation steps: 1) Apply the latest Linux kernel updates that include the patch for CVE-2022-48701 as soon as they become available from trusted Linux distributions or kernel maintainers. 2) Restrict physical access to critical Linux systems to prevent unauthorized USB device connections. 3) Employ USB device whitelisting or disable unused USB ports via BIOS/UEFI or operating system policies to limit exposure to malicious USB devices. 4) Use USB device authorization frameworks (e.g., USBGuard) to control which USB devices can connect to Linux hosts. 5) Monitor kernel logs for unusual USB audio device connection attempts or kernel errors that may indicate exploitation attempts. 6) For embedded or industrial Linux systems, ensure supply chain security to prevent insertion of malicious USB devices or firmware. 7) Educate users and administrators about the risks of connecting untrusted USB devices. These measures go beyond generic patching by focusing on access control and device management to reduce attack surface.