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Vulnerability · Published Feb 17, 2021 · Assigned by mitre

CVE-2021-26720

High 7.8

In plain English

A high-severity security flaw in the avahi package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.8High
Exploit odds (30 days)0.4%top 66.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20avahi0ALPINE-CVE-2021-26720
Alpine:v3.21avahi0ALPINE-CVE-2021-26720
Alpine:v3.22avahi0ALPINE-CVE-2021-26720
Alpine:v3.23avahi0ALPINE-CVE-2021-26720
Alpine:v3.24avahi0ALPINE-CVE-2021-26720
Debian:12avahi0.8-4DEBIAN-CVE-2021-26720
Debian:13avahi0.8-4DEBIAN-CVE-2021-26720
Debian:14avahi0.8-4DEBIAN-CVE-2021-26720

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References