An exploitable signed comparison vulnerability exists in the ARMv7 memcpy()
implementation of GNU glibc 2.30.9000. Calling memcpy() (on ARMv7 targets
that utilize the GNU glibc implementation) with a negative value for the
'num' parameter results in a signed comparison vulnerability. If an
attacker underflows the 'num' parameter to memcpy(), this vulnerability
could lead to undefined behavior such as writing to out-of-bounds memory
and potentially remote code execution. Furthermore, this memcpy()
implementation allows for program execution to continue in scenarios where
a segmentation fault or crash should have occurred. The dangers occur in
that subsequent execution and iterations of this code will be executed with
this corrupted data.