{
  "@rdf:about": "https://jvndb.jvn.jp/en/contents/2004/JVNDB-2004-000594.html",
  "dc:date": "2008-05-21T00:00+09:00",
  "dcterms:issued": "2008-05-21T00:00+09:00",
  "dcterms:modified": "2008-05-21T00:00+09:00",
  "description": "DNS cache servers consume huge resources for communication with DNS authoritative servers in the following situation.\r\n(1) a user sends a query to the DNS cache server\r\n(2) the DNS cache server sends a UDP query to an authoritative server\r\n(3) when the authoritative server finds that the reply content is too large, it sends back the reply packet to the DNS cache server with the TC bit on\r\n(4) the DNS cache server re-sends a query by TCP\r\n(5) when the authoritative server does not reply to the TCP query, or 53/tcp destined packets are dropped, the DNS cache server holds the socket in the SYN_SENT state for a certain period of time \r\n(6) a huge number of transactions in steps (1)-(5) take place in a short period of time\r\n\r\nAffected products are DNS servers with the network configuration described as above.",
  "link": "https://jvndb.jvn.jp/en/contents/2004/JVNDB-2004-000594.html",
  "sec:cpe": {
    "#text": "cpe:/a:misc:multiple_vendors",
    "@product": "(Multiple Products)",
    "@vendor": "(Multiple Venders)",
    "@version": "2.2"
  },
  "sec:cvss": {
    "@score": "5.0",
    "@severity": "Medium",
    "@type": "Base",
    "@vector": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
    "@version": "2.0"
  },
  "sec:identifier": "JVNDB-2004-000594",
  "sec:references": [
    {
      "#text": "http://jvn.jp/en/jp/JVN61857DA9/index.html",
      "@id": "JVN#61857DA9",
      "@source": "JVN"
    },
    {
      "#text": "http://www.nanog.org/mtg-0410/toyama.html",
      "@id": "NANOG Abstract",
      "@source": "NANOG"
    },
    {
      "#text": "http://www.nanog.org/mtg-0410/pdf/toyama.pdf",
      "@id": "NANOG PDF presentation",
      "@source": "NANOG"
    }
  ],
  "title": "DNS cache servers resource consumption by TCP SYN_SENT states"
}