Vulnerability in Avahi

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 /run/avahi-daemon. NOTE: this only affects the packaging for Debian GNU/Linux (used indirectly by SUSE), not the upstream Avahi product.

EPSS: 0.004 (32.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

  • cve@mitre.org (Product, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Product, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Product, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Third Party Advisory, x_refsource_MISC, Issue Tracking)
  • cve@mitre.org (Third Party Advisory, x_refsource_MISC, Broken Link)
  • cve@mitre.org (Mailing List, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Mailing List, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Third Party Advisory, x_refsource_MISC, Issue Tracking)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-26720?
CVE-2021-26720 is a high-severity vulnerability in Avahi, classified under Improper Link Resolution Before File Access. CVSS score: 7.8/10. Published 2021-02-17.
How severe is CVE-2021-26720?
High severity. CVSS v3 base score is 7.8 out of 10.