An issue was discovered in Suricata 4.1.4. By sending multiple IPv4 packets that have invalid IPv4Options, the function IPV4OptValidateTime…

An issue was discovered in Suricata 4.1.4. By sending multiple IPv4 packets that have invalid IPv4Options, the function IPV4OptValidateTimestamp in decode-ipv4.c tries to access a memory region that is not allocated. There is a check for o->len < 5 (corresponding to 2 bytes of header and 3 bytes of data). Then, "flag = *(o->data + 3)" places one beyond the 3 bytes, because the code should have been "flag = *(o->data + 1)" instead.