Vulnerability Monitor

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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.

Published

2021-02-17T22:15:12.710

Last Modified

2024-11-21T05:56:44.693

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.8 (HIGH)

CVSSv2 Vector

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

Access Vector: LOCAL
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: PARTIAL
Availability Impact: PARTIAL

Exploitability Score

3.9

Impact Score

6.4

Weaknesses

Type: Primary
CWE-59

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	avahi	avahi	≤ 0.8-4	Yes
Operating System	debian	debian_linux	9.0	Yes
Operating System	debian	debian_linux	10.0	Yes

References

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 Mailing List, Third Party Advisory ([email protected])
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 Issue Tracking, Third Party Advisory ([email protected])
https://bugzilla.suse.com/show_bug.cgi?id=1180827 Issue Tracking, Third Party Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html Mailing List, Third Party Advisory ([email protected])
https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog Broken Link, Third Party Advisory ([email protected])
https://packages.debian.org/bullseye/avahi-daemon Product, Third Party Advisory ([email protected])
https://packages.debian.org/buster/avahi-daemon Product, Third Party Advisory ([email protected])
https://packages.debian.org/sid/avahi-daemon Product, Third Party Advisory ([email protected])
https://security-tracker.debian.org/tracker/CVE-2021-26720 Third Party Advisory ([email protected])
https://www.openwall.com/lists/oss-security/2021/02/15/2 Mailing List, Third Party Advisory ([email protected])
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://bugzilla.suse.com/show_bug.cgi?id=1180827 Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog Broken Link, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://packages.debian.org/bullseye/avahi-daemon Product, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://packages.debian.org/buster/avahi-daemon Product, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://packages.debian.org/sid/avahi-daemon Product, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://security-tracker.debian.org/tracker/CVE-2021-26720 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.openwall.com/lists/oss-security/2021/02/15/2 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)