Null pointer dereference in coap_dtls_info_callback() in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a DTLS handshake where SSL_get_app_data() returns NULL.Referenceshttps://github.com/obgm/libcoap/issues/1748https://github.com/obgm/libcoap/pull/1750
