CVE-2022-49166 is a vulnerability identified in the Linux kernel's NTFS filesystem driver. The issue arises in the function ntfs_read_inode_mount, which calls ntfs_malloc_nofs with an allocation size of zero. This leads to a BUG being triggered in the __ntfs_malloc function due to the zero allocation size. The root cause is the lack of a sanity check on the attribute list size (ni->attr_list_size) before memory allocation. Without this check, the kernel attempts to allocate zero bytes, which is an invalid operation and causes a kernel BUG, potentially leading to a denial of service (system crash). The vulnerability has been addressed by adding a sanity check on the allocation size to prevent zero-byte allocations. This flaw affects the Linux kernel's NTFS driver, which is responsible for reading NTFS filesystems, commonly used in Windows environments but also supported on Linux for interoperability. The vulnerability does not appear to have known exploits in the wild and lacks a CVSS score, indicating it may be newly discovered or not yet fully assessed. The affected versions are identified by a specific commit hash, suggesting the issue is present in certain kernel versions prior to the fix. Since the flaw triggers a kernel BUG, it can cause the system to crash or reboot unexpectedly when processing malicious or malformed NTFS metadata, impacting system availability and stability. Exploitation requires the system to mount or read from an NTFS filesystem containing crafted inode attribute lists that trigger the zero allocation. No authentication or user interaction is explicitly required beyond the system processing the malicious filesystem data.

For European organizations, the primary impact of CVE-2022-49166 is on the availability and stability of Linux systems that mount NTFS filesystems. Many enterprises use Linux servers and workstations that may access NTFS volumes for interoperability with Windows systems or external storage devices. An attacker who can supply a malicious NTFS filesystem (e.g., via removable media, network shares, or virtual disk images) could cause kernel crashes, leading to denial of service conditions. This can disrupt critical services, data processing, or user productivity. While the vulnerability does not directly compromise confidentiality or integrity, repeated crashes or system instability can result in operational downtime and potential data loss if systems are not properly backed up. Organizations relying on Linux for file sharing, backup, or virtualization that involve NTFS volumes are at risk. The lack of known exploits suggests the threat is currently low but could increase if attackers develop reliable methods to trigger the flaw. The vulnerability also poses a risk in multi-tenant or cloud environments where malicious users might supply crafted NTFS images to disrupt shared infrastructure. Given the widespread use of Linux in European government, finance, telecommunications, and industrial sectors, the availability impact could be significant if exploited at scale.

1. Apply the latest Linux kernel updates that include the patch for CVE-2022-49166 to ensure the sanity check on NTFS allocation size is in place. 2. Restrict or monitor the mounting of NTFS filesystems, especially from untrusted or external sources such as USB drives, network shares, or virtual disk images. Implement policies to scan and validate NTFS volumes before mounting. 3. Use filesystem integrity and malware scanning tools to detect malformed or suspicious NTFS metadata that could trigger the vulnerability. 4. Employ kernel crash monitoring and automated recovery mechanisms to minimize downtime in case of unexpected crashes. 5. In environments where NTFS access is not required, disable or remove NTFS kernel modules to reduce the attack surface. 6. For virtualized or containerized environments, enforce strict controls on the images and filesystems that guests or containers can access, preventing injection of malicious NTFS data. 7. Maintain regular backups and disaster recovery plans to mitigate data loss from potential denial of service incidents caused by exploitation. 8. Educate system administrators and security teams about the vulnerability and encourage timely patch management and incident response readiness.