CVE-2024-53171 is a high-severity use-after-free vulnerability in the Linux kernel's UBIFS (UBI File System) authentication code, specifically within the tree node cache (TNC) management during commit operations. UBIFS is a file system designed for flash memory devices, commonly used in embedded systems and some Linux distributions. The vulnerability arises due to improper handling of parent pointers in the TNC tree structure during node insertions and deletions. When a node insertion causes a tree split, the node's parent pointer (`znode->parent`) is updated, but the cached parent pointer (`znode->cparent`) may still reference a freed node if subsequent deletions occur. This stale pointer is not reset properly in the commit phase (`ubifs_tnc_start_commit()`), leading to a use-after-free condition when `write_index()` accesses `znode->cparent`. The flaw can be triggered by repeatedly creating and deleting files with specific commands under the `CONFIG_UBIFS_FS_AUTHENTICATION` kernel configuration. The kernel's KASAN (Kernel Address Sanitizer) detects this as a use-after-free during memory copy operations in `ubifs_copy_hash()`. Exploitation could lead to arbitrary code execution, kernel crashes, or data corruption due to corrupted file system metadata. The patch involves explicitly nullifying the `cparent` pointer for root nodes during commit to prevent referencing freed memory. The vulnerability affects Linux kernel versions containing the specified commit hashes and requires local privileges with write access to UBIFS volumes configured with authentication enabled. The CVSS v3.1 score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity but requiring privileges and no user interaction.

For European organizations, the impact of CVE-2024-53171 is significant primarily in environments using Linux systems with UBIFS file systems configured with authentication, which are common in embedded devices, IoT gateways, and specialized industrial equipment. Exploitation could allow local attackers or compromised processes to escalate privileges, corrupt file system data, or cause denial of service by crashing the kernel. This could disrupt critical infrastructure, manufacturing systems, or telecommunications equipment relying on embedded Linux. Confidentiality breaches could occur if attackers manipulate file system metadata to access or alter sensitive data. Integrity and availability impacts are also high, risking data loss or system downtime. Organizations in sectors such as manufacturing, automotive, telecommunications, and critical infrastructure in Europe that deploy embedded Linux devices with UBIFS authentication are at elevated risk. The vulnerability does not appear to be exploited in the wild yet, but the high severity and ease of triggering under specific configurations warrant proactive mitigation to prevent potential targeted attacks or accidental system failures.

1. Apply the official Linux kernel patches that fix CVE-2024-53171 as soon as they are available and tested in your environment. 2. For embedded and IoT devices, coordinate with vendors to ensure updated firmware or kernel versions are deployed that include the fix. 3. Disable UBIFS authentication (`CONFIG_UBIFS_FS_AUTHENTICATION`) if it is not required, as this reduces the attack surface. 4. Implement strict access controls to limit local user privileges and prevent untrusted users or processes from performing file operations on UBIFS volumes. 5. Monitor kernel logs for KASAN or other memory error reports that may indicate exploitation attempts or system instability related to UBIFS. 6. Conduct regular integrity checks and backups of critical embedded systems to enable recovery from potential data corruption. 7. For development and testing environments, use KASAN or similar memory sanitizers to detect use-after-free and other memory errors early. 8. Harden device configurations by restricting shell or command execution capabilities on embedded devices to reduce the risk of triggering the vulnerability.