CVE-2022-49288 is a high-severity vulnerability identified in the Linux kernel's ALSA (Advanced Linux Sound Architecture) subsystem, specifically within the PCM (Pulse-code Modulation) interface. The vulnerability arises from a race condition due to the lack of synchronization when multiple concurrent writes are made to the proc filesystem entries responsible for PCM buffer preallocation. In essence, the ALSA PCM interface did not properly protect against simultaneous modifications of the PCM buffer preallocation parameters via proc files, which could lead to use-after-free (UAF) conditions or other undefined behaviors. This race condition occurs because the PCM open_mutex, which serializes access to PCM streams, was not applied to proc write operations. Exploiting this vulnerability could allow an attacker with limited privileges (local low-level privileges) to cause memory corruption, potentially leading to arbitrary code execution, privilege escalation, or system instability. The patch introduced applies the PCM open_mutex to the proc write operations, ensuring that concurrent writes and PCM stream operations are properly serialized, thereby preventing the race condition. The vulnerability is classified under CWE-416 (Use After Free), indicating that improper memory handling could be exploited. The CVSS v3.1 score is 7.8 (high), reflecting the significant impact on confidentiality, integrity, and availability, with low attack complexity and requiring low privileges but no user interaction. No known exploits are reported in the wild as of the publication date, but the potential for exploitation exists given the nature of the flaw.

For European organizations, this vulnerability poses a significant risk, especially for those running Linux-based systems in environments where ALSA is used for audio processing, such as multimedia servers, embedded systems, or workstations. The ability to exploit this flaw could allow attackers to escalate privileges from a low-privileged local user to root, compromising system confidentiality and integrity. This could lead to unauthorized access to sensitive data, disruption of services, or deployment of persistent malware. Critical infrastructure sectors, including telecommunications, manufacturing, and government agencies that rely on Linux systems, may face increased risk. Additionally, organizations using Linux in virtualized or containerized environments could see lateral movement opportunities if this vulnerability is exploited. The absence of known exploits currently reduces immediate threat levels, but the high severity and ease of exploitation mean that attackers may develop exploits in the near future, increasing risk exposure.

European organizations should promptly apply the official Linux kernel patches that address CVE-2022-49288 to ensure the PCM open_mutex is enforced during proc write operations. System administrators should audit their Linux kernel versions and update to patched releases or apply backported fixes from their Linux distribution vendors. As a practical measure, restrict access to the proc filesystem entries related to ALSA PCM buffer preallocation to trusted users only, minimizing the attack surface. Employ mandatory access controls (e.g., SELinux, AppArmor) to limit the capabilities of processes interacting with ALSA proc files. Regularly monitor system logs for unusual activity related to ALSA or proc filesystem writes. For environments where patching is delayed, consider disabling ALSA proc interfaces if feasible or isolating vulnerable systems from untrusted users. Finally, maintain robust endpoint detection and response (EDR) solutions to detect potential exploitation attempts targeting this vulnerability.