CVE-2025-0678 Details

An integer overflow vulnerability has been identified in the GRUB2 squash4 filesystem module. When the module reads data from a squash4 filesystem, it uses user-controlled parameters from the filesystem geometry to calculate the internal buffer size. However, the module fails to properly validate these calculations, allowing a maliciously crafted filesystem to manipulate the buffer size calculations. This oversight can cause the buffer size to overflow, leading to a memory allocation (grub_malloc()) with an unexpectedly small size. Consequently, the direct_read() function can perform a heap-based out-of-bounds write while reading data. This vulnerability could be exploited to corrupt GRUB's critical internal data, potentially allowing arbitrary code execution and bypassing secure boot protections.