Ubuntu.comUB:CVE-2021-26720CVE-2021-26720
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
0.0004 Low
EPSS
Percentile
5.3%
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.
Bugs
- <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982796>
- <https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1870824>
Notes
| Author | Note |
|---|---|
| mdeslaur | the script was removed in the 0.7-4ubuntu7 package in focal. for bionic and earlier, we can’t simply remove the script as libnss-mdns is too old there. |
| litios | there is no upstream patch available to fix this issue, as the proposed fix was to delete the script file. marking as deferred |
Related
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:L/Au:N/C:P/I:P/A:P
0.0004 Low
EPSS
Percentile
5.3%