Published: 17 February 2021
avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root via /etc/network/if-up.d/avahi-daemon, and allows a local attacker to cause a denial of service or create arbitrary empty files via a symlink attack on files under /run/avahi-daemon. NOTE: this only affects the packaging for Debian GNU/Linux (used indirectly by SUSE), not the upstream Avahi product.
CVSS 3 base score: 7.8
Launchpad, Ubuntu, Debian
|Ubuntu 21.04 (Hirsute Hippo)||
|Ubuntu 20.10 (Groovy Gorilla)||
|Ubuntu 20.04 LTS (Focal Fossa)||
|Ubuntu 18.04 LTS (Bionic Beaver)||
|Ubuntu 16.04 LTS (Xenial Xerus)||
|Ubuntu 14.04 ESM (Trusty Tahr)||
the script was removed in the 0.7-4ubuntu7 package in focal. for bionic and earlier, we can't simply remove the script as libnss-mdns is too old there.