CVE-2024-47677 is a vulnerability identified in the Linux kernel's exFAT filesystem driver. The issue arises in the function exfat_create_upcase_table(), which is responsible for loading and creating a case conversion table used by the exFAT filesystem implementation. Specifically, if the function exfat_load_upcase_table() reaches the end of its processing and returns the error code -EINVAL (Invalid argument), the memory that was allocated during this process is not freed properly. Subsequently, when exfat_load_default_upcase_table() is called, it allocates additional memory without releasing the previously allocated memory, leading to a memory leak. This memory leak can cause the kernel to consume increasing amounts of memory over time when handling exFAT filesystems, potentially leading to resource exhaustion. The vulnerability was identified and reported through syzkaller, a kernel fuzzing tool, which produced a crash report illustrating the issue. Although no known exploits are currently reported in the wild, the flaw represents a reliability and stability concern within Linux systems that mount or interact with exFAT filesystems. The vulnerability affects Linux kernel versions identified by the commit hash a13d1a4de3b0fe3c41d818697d691c886c5585fa and possibly others in the same development line. The issue has been publicly disclosed as of October 21, 2024, but no CVSS score has been assigned yet.

For European organizations, the impact of CVE-2024-47677 primarily concerns system stability and availability rather than direct confidentiality or integrity breaches. Organizations that rely on Linux systems with exFAT filesystem support—common in environments where removable storage devices such as USB drives or SD cards formatted with exFAT are used—may experience memory leaks that degrade system performance or cause kernel crashes over time. This can lead to denial of service conditions, particularly in critical infrastructure, enterprise servers, or embedded systems that handle large volumes of exFAT media. While the vulnerability does not appear to allow privilege escalation or remote code execution directly, the resulting instability could disrupt business operations, especially in sectors like manufacturing, telecommunications, or public services where Linux-based systems are prevalent. Additionally, memory leaks can be leveraged as part of more complex attack chains if combined with other vulnerabilities. European organizations with strict uptime requirements or those operating in regulated industries may face compliance and operational risks if systems are affected by this flaw.

To mitigate CVE-2024-47677, European organizations should prioritize updating their Linux kernels to versions where this vulnerability has been patched. Since the issue is in the exFAT driver, kernel updates from trusted Linux distributions that include the fix should be applied promptly. Organizations should audit their environments to identify systems that mount or interact with exFAT filesystems and assess the necessity of exFAT support; if not required, disabling or unloading the exFAT kernel module can reduce exposure. Monitoring system memory usage and kernel logs for unusual patterns or crashes related to exFAT operations can help detect exploitation attempts or the effects of the memory leak. For embedded or specialized Linux systems, vendors should be contacted to ensure firmware or kernel updates are available and applied. Additionally, implementing strict controls on removable media usage and scanning devices before connection can reduce the risk of triggering the vulnerability. Finally, organizations should incorporate this vulnerability into their vulnerability management and incident response plans to ensure timely detection and remediation.