A: Root Cause Analysis: Looking at the given vulnerable code line and its context, the CWE-787 (Out-of-bounds Write) vulnerability exists in the code because the `len` variable is not checked to ensure that it is positive before allocating memory for the `path` variable. If `len` is 0 or negative, then allocating memory for `path` with `len` can lead to an out-of-bounds write vulnerability, which is CWE-787.