CVE-2024-35924 is a vulnerability identified in the Linux kernel's USB Type-C subsystem, specifically within the USB Type-C Connector System Software Interface (UCSI) driver. The issue arises from a mismatch in the expected size of the MESSAGE_IN region between UCSI versions 1.2 and 2.0. In UCSI 1.2, the MESSAGE_IN region size is 16 bytes, whereas in UCSI 2.0, it was increased to 256 bytes. The vulnerability occurs because older systems running UCSI 1.2 may not properly limit read operations to the smaller 16-byte size, potentially allowing an overflow when reading from the MESSAGE_IN region. This can lead to out-of-bounds reads, which may expose kernel memory contents or cause kernel instability. The patch introduced adds a mechanism to detect the UCSI version in use and truncate read sizes accordingly for UCSI 1.2, preventing overflow. This vulnerability is rooted in the kernel's USB Type-C driver code and affects Linux kernel versions that include the vulnerable UCSI implementation prior to the patch. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability could have several impacts depending on the deployment environment. Linux is widely used in servers, desktops, and embedded devices across Europe, including critical infrastructure, government, and enterprise environments. Exploitation of this vulnerability could lead to kernel memory disclosure or denial of service through kernel crashes, potentially allowing attackers to gain sensitive information or disrupt services. Although no active exploits are known, the vulnerability affects the kernel's USB Type-C subsystem, which is commonly used in modern hardware for device connectivity. Organizations relying on Linux systems with USB Type-C hardware interfaces are at risk, especially if they use older kernel versions without the patch. This could impact data confidentiality and system availability, particularly in sectors with high reliance on Linux-based systems such as finance, telecommunications, and public administration.

European organizations should promptly identify Linux systems running vulnerable kernel versions with UCSI 1.2 support. Specific mitigation steps include: 1) Applying the official Linux kernel patches that implement the read size truncation for UCSI 1.2 to prevent overflow conditions. 2) Updating Linux distributions to the latest stable kernel versions where this vulnerability is resolved. 3) For critical systems where immediate patching is not feasible, consider disabling USB Type-C interfaces or restricting physical access to USB ports to reduce attack surface. 4) Implement kernel hardening and monitoring to detect abnormal kernel behavior or crashes related to USB subsystem. 5) Engage with hardware vendors to ensure firmware compatibility and updates that support secure UCSI implementations. These targeted actions go beyond generic advice by focusing on the specific USB Type-C UCSI driver and its versioning nuances.