The OpenSSL project reports:
0-byte record padding oracle (CVE-2019-1559) (Moderate)
If an application encounters a fatal protocol error and then calls
SSL_shutdown() twice (once to send a close_notify, and once to receive
one) then OpenSSL can respond differently to the calling application if
a 0 byte record is received with invalid padding compared to if a 0 byte
record is received with an invalid MAC. If the application then behaves
differently based on that in a way that is detectable to the remote peer,
then this amounts to a padding oracle that could be used to decrypt data.