I am able to reproduce, but only on IPv6. Passing the -4 flag to dig resulted in connection timed out.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to avahi in Ubuntu. https://bugs.launchpad.net/bugs/1570788 Title: Makes mDNS ddos amplification attack possible Status in avahi package in Ubuntu: New Bug description: Apparently mDNS can be used for ddos amplification, see for instance https://mdns.shadowserver.org/ and https://www.us-cert.gov/ncas/alerts/TA14-017A Steps to reproduce: dig @rusk.hpc2n.umu.se -p 5353 -t ptr _services._dns-sd._udp.local The response is supposedly 2-10 times the size of the query, making for a moderate but noticeable amplification. Workarounds are easy, but not responding outside localnet by default is probably reasonable for mDNS. Reproduced at at least trusty and precise, would be very surprised if it didn't also apply to xenial but I left my xenial laptop at home today. :) ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: avahi-daemon 0.6.30-5ubuntu2.1 ProcVersionSignature: Ubuntu 3.13.0-83.127~precise1-generic 3.13.11-ckt35 Uname: Linux 3.13.0-83-generic x86_64 NonfreeKernelModules: openafs ApportVersion: 2.0.1-0ubuntu17.13 Architecture: amd64 Date: Fri Apr 15 12:12:22 2016 MarkForUpload: True ProcEnviron: LANGUAGE=en_US:en TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: avahi UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1570788/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
