CVE-2021-26720
Avahi Debian if-up.d Denial of Service (DoS) and File Creation Vulnerability
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.
INFO
Published Date :
Feb. 17, 2021, 10:15 p.m.
Last Modified :
Dec. 6, 2022, 9:52 p.m.
Source :
[email protected]
Remotely Exploitable :
No
Impact Score :
5.9
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-26720.
| URL | Resource |
|---|---|
| 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 |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-26720 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-26720 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Modified Analysis by [email protected]
Dec. 06, 2022
Action Type Old Value New Value Changed Reference Type https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html No Types Assigned https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html Mailing List, Third Party Advisory -
CVE Modified by [email protected]
Jun. 07, 2022
Action Type Old Value New Value Added Reference https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html [No Types Assigned] -
Initial Analysis by [email protected]
Feb. 25, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:P/I:P/A:P) Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Changed Reference Type https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 No Types Assigned https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796 Mailing List, Third Party Advisory Changed Reference Type https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 No Types Assigned https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824 Issue Tracking, Third Party Advisory Changed Reference Type https://bugzilla.suse.com/show_bug.cgi?id=1180827 No Types Assigned https://bugzilla.suse.com/show_bug.cgi?id=1180827 Issue Tracking, Third Party Advisory Changed Reference Type https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog No Types Assigned https://metadata.ftp-master.debian.org/changelogs/main/a/avahi/avahi_0.8-4_changelog Broken Link, Third Party Advisory Changed Reference Type https://packages.debian.org/bullseye/avahi-daemon No Types Assigned https://packages.debian.org/bullseye/avahi-daemon Product, Third Party Advisory Changed Reference Type https://packages.debian.org/buster/avahi-daemon No Types Assigned https://packages.debian.org/buster/avahi-daemon Product, Third Party Advisory Changed Reference Type https://packages.debian.org/sid/avahi-daemon No Types Assigned https://packages.debian.org/sid/avahi-daemon Product, Third Party Advisory Changed Reference Type https://security-tracker.debian.org/tracker/CVE-2021-26720 No Types Assigned https://security-tracker.debian.org/tracker/CVE-2021-26720 Third Party Advisory Changed Reference Type https://www.openwall.com/lists/oss-security/2021/02/15/2 No Types Assigned https://www.openwall.com/lists/oss-security/2021/02/15/2 Mailing List, Third Party Advisory Added CWE NIST CWE-59 Added CPE Configuration OR *cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:* versions up to (including) 0.8-4 Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-26720 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-26720
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.04 }} 0.00%
score
0.05635
percentile