1. DNS/用語/オープンリゾルバー/PowerDNS

について、ここに記述してください。

https://public-dns.info/nameserver/gb.html

5.133.41.1 ns2.solwaycomms.net. 

$ dig -t txt xyy2x.sub.mufj.jp @5.133.41.1 

; <<>> DiG 9.10.8-P1 <<>> -t txt xyy2x.sub.mufj.jp @5.133.41.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22087
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;xyy2x.sub.mufj.jp.             IN      TXT

;; ANSWER SECTION:
xyy2x.sub.mufj.jp.      3600    IN      TXT     "Your_cache_server_is_vulnerable."

;; Query time: 763 msec
;; SERVER: 5.133.41.1#53(5.133.41.1)
;; WHEN: Tue Nov 13 22:31:03 JST 2018
;; MSG SIZE  rcvd: 80

$ dig -t txt xshy.sub.mufj.jp @80.252.82.166

; <<>> DiG 9.10.8-P1 <<>> -t txt xshy.sub.mufj.jp @80.252.82.166
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53958
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;xshy.sub.mufj.jp.              IN      TXT

;; ANSWER SECTION:
xshy.sub.mufj.jp.       3600    IN      TXT     "Your_cache_server_is_vulnerable."

;; Query time: 801 msec
;; SERVER: 80.252.82.166#53(80.252.82.166)
;; WHEN: Tue Nov 13 23:33:57 JST 2018
;; MSG SIZE  rcvd: 79

2. PowerDNS Recursor 4.0.8

194.187.251.67 manchester-ns01.cyberghostvpn.com. 

$ dig -t txt xyytt.sub.mufj.jp @194.187.251.67 

; <<>> DiG 9.10.8-P1 <<>> -t txt xyytt.sub.mufj.jp @194.187.251.67
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 30719
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;xyytt.sub.mufj.jp.             IN      TXT

;; ANSWER SECTION:
xyytt.sub.mufj.jp.      3600    IN      TXT     "Your_cache_server_is_vulnerable."

;; Query time: 743 msec
;; SERVER: 194.187.251.67#53(194.187.251.67)
;; WHEN: Tue Nov 13 22:34:32 JST 2018
;; MSG SIZE  rcvd: 91

version.bind.           5       CH      TXT     "Served by PowerDNS - http://www.powerdns.com"
version.bind.           86400   CH      TXT     "PowerDNS Recursor 4.0.3 (built Sep  6 2016 13:00:54 by root@d05101f35f6b)"
version.bind.           5       CH      TXT     "PowerDNS Authoritative Server 3.3.1 (jenkins@autotest.powerdns.com built 20131217194128 mockbuild@)"
version.bind.           5       CH      TXT     "PowerDNS Authoritative Server 3.3.1 (jenkins@autotest.powerdns.com built 20131217194128 mockbuild@)"
version.bind.           86400   CH      TXT     "PowerDNS Recursor 3.1.4 $Id: pdns_recursor.cc 917 2006-11-07 12:23:51Z ahu $"