High severity · published Feb 17, 2021
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…
7.8
CVSS
0.4%
EPSS
No
On KEV
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
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AV
Avahi · Avahi
through 0.8-4 · source: NVD
DL
Debian Linux · Debian
9.0; 10.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-26720
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-26720
Mailing List
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796
Issue Tracking
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824
Issue Tracking
https://bugzilla.suse.com/show_bug.cgi?id=1180827
Mailing List
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html
Broken Link
https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog
Product
https://packages.debian.org/bullseye/avahi-daemon
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