CVE-2021-26720

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.
Link Following
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
7.8 HIGH
LOCAL
LOW
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
mitreCNA
---
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CVEADP
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Base Score
CVSS 3.x
EPSS Score
Percentile: 13%
VendorProductVersion
avahiavahi
𝑥
≤ 0.8-4
debiandebian_linux
9.0
debiandebian_linux
10.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
avahi
bullseye
0.8-5+deb11u2
fixed
bookworm
0.8-10
fixed
sid
0.8-13
fixed
trixie
0.8-13
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
avahi
noble
not-affected
mantic
not-affected
lunar
not-affected
kinetic
not-affected
jammy
not-affected
impish
not-affected
hirsute
not-affected
groovy
not-affected
focal
not-affected
bionic
deferred
xenial
deferred
trusty
deferred
Common Weakness Enumeration
References
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824
https://bugzilla.suse.com/show_bug.cgi?id=1180827
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html
https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog
https://packages.debian.org/bullseye/avahi-daemon
https://packages.debian.org/buster/avahi-daemon
https://packages.debian.org/sid/avahi-daemon
https://security-tracker.debian.org/tracker/CVE-2021-26720
https://www.openwall.com/lists/oss-security/2021/02/15/2
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824
https://bugzilla.suse.com/show_bug.cgi?id=1180827
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html
https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog
https://packages.debian.org/bullseye/avahi-daemon
https://packages.debian.org/buster/avahi-daemon
https://packages.debian.org/sid/avahi-daemon
https://security-tracker.debian.org/tracker/CVE-2021-26720
https://www.openwall.com/lists/oss-security/2021/02/15/2