CVE-2024-27413 is a vulnerability identified in the Linux kernel specifically within the EFI (Extensible Firmware Interface) capsule loader component. The issue arises from an incorrect memory allocation size in the function 'efi_capsule_open' located in the file drivers/firmware/efi/capsule-loader.c. The vulnerability is due to the use of sizeof(void *) for allocating memory intended to hold a phys_addr_t type, which on 32-bit architectures is insufficient because phys_addr_t is 64 bits (8 bytes) while sizeof(void *) is only 4 bytes. This discrepancy leads to an allocation size that is too small, potentially causing memory corruption or undefined behavior when the system attempts to use the allocated memory as a phys_addr_t. The problem was detected by the GCC 14 compiler, which flagged the allocation as an error due to the insufficient size. The fix involves correcting the allocation to use the appropriate size for phys_addr_t rather than sizeof(void *). This vulnerability is rooted in a low-level kernel component responsible for handling firmware capsules, which are used for firmware updates and other system-level operations. Although no known exploits are currently reported in the wild, the vulnerability could theoretically be leveraged to cause kernel memory corruption, leading to system instability, crashes, or potentially privilege escalation if exploited by a local attacker. The affected versions are specific Linux kernel commits identified by their hashes, indicating that the issue is present in certain recent kernel builds prior to the patch. The vulnerability does not require user interaction but does require the ability to trigger the EFI capsule loader code path, which may limit the attack surface to privileged or local users or specific system configurations that utilize EFI capsule loading.

For European organizations, the impact of CVE-2024-27413 depends largely on the deployment of Linux systems that utilize EFI capsule loading, particularly on 32-bit architectures. Many European enterprises, government agencies, and critical infrastructure operators rely on Linux-based servers and embedded systems. If these systems run vulnerable kernel versions, they could be exposed to kernel memory corruption risks, potentially leading to denial of service or privilege escalation. This could disrupt business operations, compromise system integrity, or enable attackers to gain unauthorized access to sensitive data. The risk is heightened in sectors with strict regulatory requirements such as finance, healthcare, and energy, where system availability and data confidentiality are paramount. Additionally, embedded Linux devices used in industrial control systems or IoT deployments across Europe could be affected if they use vulnerable kernel versions and EFI capsule loading. However, the lack of known exploits and the requirement for specific conditions to trigger the vulnerability somewhat limit immediate widespread impact. Nonetheless, the vulnerability represents a latent risk that could be exploited in targeted attacks, especially in environments where attackers have local access or can influence firmware update processes.

To mitigate CVE-2024-27413, European organizations should prioritize updating their Linux kernels to versions where this vulnerability has been patched. Kernel maintainers have corrected the allocation size to properly match phys_addr_t, eliminating the risk of memory corruption in the EFI capsule loader. Organizations should: 1) Identify all Linux systems, especially those running on 32-bit architectures or embedded devices, that may be affected. 2) Apply the latest kernel updates from trusted sources or distributions that have incorporated the fix. 3) For systems where immediate patching is not feasible, consider disabling EFI capsule loading if it is not required, to reduce the attack surface. 4) Monitor system logs and firmware update processes for anomalies that could indicate exploitation attempts. 5) Implement strict access controls to limit who can trigger firmware update mechanisms or load EFI capsules. 6) Conduct thorough testing of kernel updates in staging environments to ensure stability before deployment. These steps go beyond generic advice by focusing on the specific subsystem affected and the operational context of EFI capsule loading.