CVE-2021-26720 — Link Following in Avahi

CWE-59 — Link Following5 documents5 sources
Severity
7.8HIGHNVD
EPSS
0.1%
top 78.80%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
10
AvahiDebian AvahiDebian Linux+7 more
Timeline
PublishedFeb 17
Latest updateMay 24

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 vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9

Affected Packages10 packages

▶debiandebian/avahi< avahi 0.8-4 (bookworm)
▶Debianavahi/avahi< 0.8-4+3
▶NVDavahi/avahi0.8-4

Also affects: Debian Linux 10.0, 9.0

🔴Vulnerability Details

2
GHSA
GHSA-jhxr-wvf5-hrp6: avahi-daemon-check-dns↗2022-05-24
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OSV
CVE-2021-26720: avahi-daemon-check-dns↗2021-02-17
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📋Vendor Advisories

2
Microsoft
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 arbitra↗2021-02-09
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Debian
CVE-2021-26720: avahi - avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed ...↗2021
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