abuse.ch DNSSEC Outage: 2020-10-15
Date: October 15, 2020
Overview
This page gives some details on the abuse.ch DNSSEC outage on October 15, 2020. abuse.ch runs multiple important blocklists that target the Zeus botnet, ransomware and more. It has many users.
Timeline / DNSViz
- 2020-10-15 16:40:09 UTC — Expired RRSIGs
Verisign's DNSSEC Debugger
Verisign doesn't archive test results, to here's a screenshot I took of my web browser's output on October 15, 2020:
Google DNS: with and without DNSSEC
DNSSEC can be disabled in queries via the CD (checking disabled) bit. Let's compare DNS queries with and without DNSSEC.
$ dig +dnssec a mail.abuse.ch. @8.8.8.8
; <<>> dig 9.10.8-P1 <<>> +dnssec a mail.abuse.ch. @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 29739
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 512
;; QUESTION SECTION:
;mail.abuse.ch. IN A
;; Query time: 36 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Oct 15 16:40:36 UTC 2020
;; MSG SIZE rcvd: 42
You have to disable DNSSEC to make DNS queries work:
$ dig +cd a mail.abuse.ch. @8.8.8.8
; <<>> dig 9.10.8-P1 <<>> +cd a mail.abuse.ch. @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12091
;; flags: qr rd ra cd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;mail.abuse.ch. IN A
;; ANSWER SECTION:
mail.abuse.ch. 59 IN A 207.154.212.14
;; Query time: 28 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Oct 15 16:40:36 UTC 2020
;; MSG SIZE rcvd: 58
drill trace
Since DNSSEC contains so much garbage, I put the complete drill trace into its own file, with the relevant portion below (emphasis added):
;; Domain: abuse.ch.
[B] abuse.ch. 3600 IN DNSKEY 257 3 13 ;{id = 6875 (ksk), size = 256b}
abuse.ch. 3600 IN DNSKEY 256 3 5 ;{id = 29418 (zsk), size = 2048b}
abuse.ch. 3600 IN DNSKEY 257 3 5 ;{id = 61972 (ksk), size = 2048b}
abuse.ch. 3600 IN DNSKEY 256 3 13 ;{id = 621 (zsk), size = 256b}
[B] Error verifying denial of existence for mail.abuse.ch. DS: No keys with the keytag and algorithm from the RRSIG found
;; No ds record for delegation
;; Domain: mail.abuse.ch.
;; No DNSKEY record found for mail.abuse.ch.
[B] mail.abuse.ch. 60 IN A 207.154.212.14
;; Error: No keys with the keytag and algorithm from the RRSIG found
;;[S] self sig OK; [B] bogus; [T] trusted