The file_check_mem function in funcs.c in file before 5.23, as used in the Fileinfo component in PHP before 5.5.34, 5.6.x before 5.6.20, and 7.x before 7.0.5, mishandles continuation-level jumps, which allows context-dependent attackers to cause a denial of service (buffer overflow and application crash) or possibly execute arbitrary code via a crafted magic file.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.