stb_vorbis is a single file MIT licensed library for processing ogg vorbis files. A crafted file may trigger out of bounds write in f->vendor[len] = (char)'\0';
. The root cause is that if the len read in start_decoder
is -1
and len + 1
becomes 0 when passed to setup_malloc
. The setup_malloc
behaves differently when f->alloc.alloc_buffer
is pre-allocated. Instead of returning NULL
as in malloc
case it shifts the pre-allocated buffer by zero and returns the currently available memory block. This issue may lead to code execution.