CVE-2024-27028 is a medium-severity vulnerability identified in the Linux kernel's SPI (Serial Peripheral Interface) driver, specifically within the spi-mt65xx module. The issue arises due to a NULL pointer dereference in the interrupt handler of the SPI driver. The vulnerability occurs because the transmit (TX) buffer pointer in the spi_transfer function can be NULL. If the interrupt handler attempts to access or write to this NULL pointer, it results in an invalid memory access, causing the kernel to crash or become unstable. This is classified under CWE-476 (NULL Pointer Dereference). The root cause is the lack of a proper check for the validity of the tx_buf pointer before its use in the interrupt context. The fix involves adding a check to ensure trans->tx_buf is not NULL before it is dereferenced. This vulnerability does not require any privileges or user interaction to be exploited, and the attack vector is network-based (AV:N), meaning it can be triggered remotely if the vulnerable SPI driver is exposed. The CVSS v3.1 base score is 6.5, reflecting a medium severity with no confidentiality impact, limited integrity impact, and significant availability impact due to potential system crashes. No known exploits are currently reported in the wild, but the vulnerability's nature means it could be used for denial-of-service (DoS) attacks against affected Linux systems using the spi-mt65xx driver. The affected versions are identified by specific kernel commit hashes, indicating the vulnerability is present in certain Linux kernel builds prior to the patch. This vulnerability is relevant for embedded systems or devices using the MT65xx SPI controller, which is common in some mobile and IoT devices running Linux kernels with this driver module included.

For European organizations, the primary impact of CVE-2024-27028 is the potential for denial-of-service conditions on devices running vulnerable Linux kernels with the spi-mt65xx driver. This could affect embedded systems, industrial control systems, IoT devices, or specialized hardware using this SPI controller. Disruption of these systems could lead to operational downtime, impacting critical infrastructure, manufacturing, or telecommunications sectors. While there is no direct confidentiality breach, the availability impact could indirectly affect business continuity and service reliability. Organizations relying on Linux-based embedded devices or custom hardware with this driver should be particularly vigilant. The lack of authentication or user interaction required for exploitation increases the risk, especially if devices are exposed to untrusted networks. However, the absence of known exploits in the wild currently reduces immediate risk, though proactive patching is advised to prevent future attacks.

1. Identify and inventory all Linux systems and embedded devices using the spi-mt65xx driver, especially those running kernels prior to the patch commit. 2. Apply the official Linux kernel patches that include the fix for CVE-2024-27028 as soon as they are available from trusted sources or distributions. 3. For devices where kernel updates are not feasible, consider isolating them from untrusted networks or implementing network-level filtering to block potential attack vectors targeting SPI interfaces. 4. Monitor system logs and kernel crash reports for signs of NULL pointer dereference or unexpected reboots that may indicate exploitation attempts. 5. Engage with hardware vendors or device manufacturers to obtain updated firmware or kernel versions that address this vulnerability. 6. Implement robust incident response plans to quickly address any denial-of-service incidents related to this vulnerability. 7. For critical infrastructure, consider deploying redundancy and failover mechanisms to mitigate availability impacts.