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.

CVSS v3.0 7.8 HIGH
CVSS v2.0 4.6 MEDIUM

7.8^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

4.6^/10

CVSS v2.0 : MEDIUM

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

Exploitability : 3.9 / Impact : 6.4

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://packages.debian.org/buster/avahi-daemon	Product Third Party Advisory
https://packages.debian.org/sid/avahi-daemon	Product Third Party Advisory
https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog	Broken Link Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796	Mailing List Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1180827	Issue Tracking Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2021-26720	Third Party Advisory
https://packages.debian.org/bullseye/avahi-daemon	Product Third Party Advisory
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824	Issue Tracking Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/02/15/2	Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html	Mailing List Third Party Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:*

Configuration 2 (hide)

OR	cpe:2.3:o:debian:debian_linux:9.0:::::::*
	cpe:2.3:o:debian:debian_linux:10.0:::::::*

Information

Published : 2021-02-17 14:15

Updated : 2022-12-06 13:52

NVD link : CVE-2021-26720

Mitre link : CVE-2021-26720

JSON object : View

CWE

CWE-59

Improper Link Resolution Before File Access ('Link Following')

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Products Affected

debian

debian_linux

avahi

avahi

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