CVEvulnerability
CVE-2021-26720
7.8 HIGH
Official page ↗
- Status
- Modified
- Published
- 2021-02-17
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CVSS 2.0 ([email protected])
- 4.6 MEDIUM — AV:L/AC:L/Au:N/C:P/I:P/A:P
- Weaknesses
- CWE-59
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.
Affected configurations
• avahi avahi (<= 0.8-4)
• debian debian linux 9.0
• debian debian linux 10.0
Related
Weakness · CWE (1)
- CWE-59 Improper Link Resolution Before File Access weakness
References
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 Mailing List, Third Party Advisory
- https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 Issue Tracking, Third Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1180827 Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html Mailing List, Third Party Advisory
- https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog Broken Link, Third Party Advisory
- https://packages.debian.org/bullseye/avahi-daemon Product, Third Party Advisory
- https://packages.debian.org/buster/avahi-daemon Product, Third Party Advisory
- https://packages.debian.org/sid/avahi-daemon Product, Third Party Advisory
- https://security-tracker.debian.org/tracker/CVE-2021-26720 Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/02/15/2 Mailing List, Third Party Advisory
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 Mailing List, Third Party Advisory
- https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 Issue Tracking, Third Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1180827 Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html Mailing List, Third Party Advisory
- https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog Broken Link, Third Party Advisory
- https://packages.debian.org/bullseye/avahi-daemon Product, Third Party Advisory
- https://packages.debian.org/buster/avahi-daemon Product, Third Party Advisory
- https://packages.debian.org/sid/avahi-daemon Product, Third Party Advisory
- https://security-tracker.debian.org/tracker/CVE-2021-26720 Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/02/15/2 Mailing List, Third Party Advisory