Type confusion in FalkorDB GRAPH.QUERY via the --bolt argument

A type confusion vulnerability in the _read_flags function (src/commands/cmd_dispatcher.c) in FalkorDB before 4.20.0 allows a remote authenticated attacker who can run GRAPH.QUERY to cause a denial of service and possibly disclose or corrupt memory. The function accepts a --bolt argument from any client and casts the following command argument, a Redis string object, to a Bolt client structure without checking its origin; the result-set code then dereferences pointers read from that object. The argument is parsed even when the Bolt endpoint is disabled, so default configurations are affected.