CVE-2021-26720

high

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.

References

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

https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html

Details

Source: MITRE

Published: 2021-02-17

Updated: 2022-06-07

Type: CWE-59

Risk Information

CVSS v2

Base Score: 4.6

Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P

Impact Score: 6.4

Exploitability Score: 3.9

Severity: MEDIUM

CVSS v3

Base Score: 7.8

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

Impact Score: 5.9

Exploitability Score: 1.8

Severity: HIGH