CVE-2021-26720 Information

Description

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 Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

https://packages.debian.org/buster/avahi-daemon https://packages.debian.org/sid/avahi-daemon https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 https://bugzilla.suse.com/show_bug.cgi?id=1180827 https://security-tracker.debian.org/tracker/CVE-2021-26720 https://packages.debian.org/bullseye/avahi-daemon https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 https://www.openwall.com/lists/oss-security/2021/02/15/2

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8