Invalid JSON format

[stanley101music]

Cloudflare is using "Black Lies". For an NXDOMAIN, they always return \000.(the missing name) as the next name. Thus the \0 will cause the invalid escape in JSON format

For example, the result of querying cloudflare.com @1.1.1.1 CNAME

{
  "answer_ipv4_address":"1.1.1.1",
  "answer_type": 800,
  "canonical_name":"cloudflare.com.",
  "replies_full":
  [
    [152,147,129,144,0,1,0,0,0,4,0,1,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,0,5,0,1,192,12,0,6,0,1,0,0,0,107,0,32,3,110,115,51,192,12,3,100,110,115,192,12,138,130,153,176,0,0,39,16,0,0,9,96,0,9,58,128,0,0,1,44,192,12,0,46,0,1,0,0,0,107,0,98,0,6,13,2,0,0,1,44,101,60,182,191,101,57,247,159,134,201,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,183,234,115,136,64,163,165,26,8,194,55,69,253,4,113,81,5,71,142,63,84,90,142,18,78,198,80,28,41,122,100,182,31,121,94,119,47,196,47,53,216,114,221,143,174,123,74,62,104,106,166,176,44,237,208,0,158,222,144,87,170,22,72,157,192,12,0,47,0,1,0,0,0,107,0,32,1,0,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,0,9,98,5,128,12,84,11,141,28,192,1,1,192,192,12,0,46,0,1,0,0,0,107,0,98,0,47,13,2,0,0,1,44,101,60,182,191,101,57,247,159,134,201,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,1,3,226,52,83,96,21,14,6,7,218,209,197,176,162,32,32,237,132,135,21,213,195,99,22,174,55,248,74,168,34,34,133,248,193,174,67,35,145,124,183,55,114,253,37,243,181,216,221,93,191,176,184,78,127,154,20,131,215,247,44,94,103,41,0,0,41,4,208,0,0,128,0,0,0]
  ],
  "replies_tree":
  [
    {
      "additional":
      [
        {
          "do": 1,
          "extended_rcode": 0,
          "rdata":
          {
            "rdata_raw":[]
          },
          "type": 41,
          "udp_payload_size": 1232,
          "version": 0,
          "z": 0
        }
      ],
      "answer": [],
      "answer_ipv4_address":"1.1.1.1",
      "answer_type": 800,
      "authority":
      [
        {
          "class": 1,
          "name":"cloudflare.com.",
          "rdata":
          {
            "expire": 604800,
            "minimum": 300,
            "mname":"ns3.cloudflare.com.",
            "rdata_raw":[3,110,115,51,192,12,3,100,110,115,192,12,138,130,153,176,0,0,39,16,0,0,9,96,0,9,58,128,0,0,1,44],
            "refresh": 10000,
            "retry": 2400,
            "rname":"dns.cloudflare.com.",
            "serial": -1971152464
          },
          "ttl": 107,
          "type": 6
        },
        {
          "class": 1,
          "name":"cloudflare.com.",
          "rdata":
          {
            "algorithm": 13,
            "key_tag": 34505,
            "labels": 2,
            "original_ttl": 300,
            "rdata_raw":[0,6,13,2,0,0,1,44,101,60,182,191,101,57,247,159,134,201,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,183,234,115,136,64,163,165,26,8,194,55,69,253,4,113,81,5,71,142,63,84,90,142,18,78,198,80,28,41,122,100,182,31,121,94,119,47,196,47,53,216,114,221,143,174,123,74,62,104,106,166,176,44,237,208,0,158,222,144,87,170,22,72,157],
            "signature":[183,234,115,136,64,163,165,26,8,194,55,69,253,4,113,81,5,71,142,63,84,90,142,18,78,198,80,28,41,122,100,182,31,121,94,119,47,196,47,53,216,114,221,143,174,123,74,62,104,106,166,176,44,237,208,0,158,222,144,87,170,22,72,157],
            "signature_expiration": 1698477759,
            "signature_inception": 1698297759,
            "signers_name":"cloudflare.com.",
            "type_covered": 6
          },
          "ttl": 107,
          "type": 46
        },
        {
          "class": 1,
          "name":"cloudflare.com.",
          "rdata":
          {
            "next_domain_name":"\000.cloudflare.com.",
            "rdata_raw":[1,0,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,0,9,98,5,128,12,84,11,141,28,192,1,1,192],
            "type_bit_maps":[0,9,98,5,128,12,84,11,141,28,192,1,1,192]
          },
          "ttl": 107,
          "type": 47
        },
        {
          "class": 1,
          "name":"cloudflare.com.",
          "rdata":
          {
            "algorithm": 13,
            "key_tag": 34505,
            "labels": 2,
            "original_ttl": 300,
            "rdata_raw":[0,47,13,2,0,0,1,44,101,60,182,191,101,57,247,159,134,201,10,99,108,111,117,100,102,108,97,114,101,3,99,111,109,0,1,3,226,52,83,96,21,14,6,7,218,209,197,176,162,32,32,237,132,135,21,213,195,99,22,174,55,248,74,168,34,34,133,248,193,174,67,35,145,124,183,55,114,253,37,243,181,216,221,93,191,176,184,78,127,154,20,131,215,247,44,94,103,41],
            "signature":[1,3,226,52,83,96,21,14,6,7,218,209,197,176,162,32,32,237,132,135,21,213,195,99,22,174,55,248,74,168,34,34,133,248,193,174,67,35,145,124,183,55,114,253,37,243,181,216,221,93,191,176,184,78,127,154,20,131,215,247,44,94,103,41],
            "signature_expiration": 1698477759,
            "signature_inception": 1698297759,
            "signers_name":"cloudflare.com.",
            "type_covered": 47
          },
          "ttl": 107,
          "type": 46
        }
      ],
      "canonical_name":"cloudflare.com.",
      "dnssec_status": 401,
      "header":
      {
        "aa": 0,
        "ad": 0,
        "ancount": 0,
        "arcount": 1,
        "cd": 1,
        "extended_rcode": 0,
        "id": 39059,
        "nscount": 4,
        "opcode": 0,
        "qdcount": 1,
        "qr": 1,
        "ra": 1,
        "rcode": 0,
        "rd": 1,
        "tc": 0,
        "z": 0
      },
      "question":
      {
        "qclass": 1,
        "qname":"cloudflare.com.",
        "qtype": 5
      }
    }
  ],
  "status": 902
}

"next_domain_name":"\000.cloudflare.com." Although the answer part is empty, the authority part will contain the response of NSEC, and cause the invalid escape due to \0 It's just an example of known invalid escape, there might be other possible responses that cause the same issue.