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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.40% probability · 33th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-59
- Affected
- avahi/avahi · debian/debian linux
- Source
- cve@mitre.org
References
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796Mailing List, Third Party Advisory
- https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824Issue Tracking, Third Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1180827Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/06/msg00009.htmlMailing List, Third Party Advisory
- https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelogBroken Link, Third Party Advisory
- https://packages.debian.org/bullseye/avahi-daemonProduct, Third Party Advisory
- https://packages.debian.org/buster/avahi-daemonProduct, Third Party Advisory
- https://packages.debian.org/sid/avahi-daemonProduct, Third Party Advisory
- https://security-tracker.debian.org/tracker/CVE-2021-26720Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/02/15/2Mailing List, Third Party Advisory
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796Mailing List, Third Party Advisory
- https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824Issue Tracking, Third Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1180827Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/06/msg00009.htmlMailing List, Third Party Advisory
- https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelogBroken Link, Third Party Advisory
- https://packages.debian.org/bullseye/avahi-daemonProduct, Third Party Advisory
- https://packages.debian.org/buster/avahi-daemonProduct, Third Party Advisory
- https://packages.debian.org/sid/avahi-daemonProduct, Third Party Advisory
- https://security-tracker.debian.org/tracker/CVE-2021-26720Third Party Advisory
- https://www.openwall.com/lists/oss-security/2021/02/15/2Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.