{"id":"UBUNTU-CVE-2021-3468","details":"A flaw was found in avahi in versions 0.6 up to 0.8. The event used to signal the termination of the client connection on the avahi Unix socket is not correctly handled in the client_work function, allowing a local attacker to trigger an infinite loop. The highest threat from this vulnerability is to the availability of the avahi service, which becomes unresponsive after this flaw is triggered.","modified":"2026-04-22T12:55:04.689658Z","published":"2021-06-02T16:15:00Z","related":["USN-5008-1","USN-5008-2"],"upstream":["CVE-2021-3468"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-3468"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5008-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5008-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-3468"}],"affected":[{"package":{"name":"avahi","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/avahi@0.6.31-4ubuntu1.3+esm1?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.31-4ubuntu1.3+esm1"}]}],"versions":["0.6.31-2ubuntu4","0.6.31-2ubuntu5","0.6.31-3ubuntu1","0.6.31-4ubuntu1","0.6.31-4ubuntu1.1","0.6.31-4ubuntu1.2","0.6.31-4ubuntu1.3"],"ecosystem_specific":{"binaries":[{"binary_name":"avahi-autoipd","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"avahi-daemon","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"avahi-discover","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"avahi-dnsconfd","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"avahi-ui-utils","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"avahi-utils","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-client3","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-common-data","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-common3","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-compat-libdnssd1","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-core7","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-glib1","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-gobject0","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-qt4-1","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-ui-gtk3-0","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"libavahi-ui0","binary_version":"0.6.31-4ubuntu1.3+esm1"},{"binary_name":"python-avahi","binary_version":"0.6.31-4ubuntu1.3+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3468.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/avahi@0.6.32~rc+dfsg-1ubuntu2.3+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"}]}],"versions":["0.6.31-4ubuntu4","0.6.32~rc+dfsg-1ubuntu2","0.6.32~rc+dfsg-1ubuntu2.1","0.6.32~rc+dfsg-1ubuntu2.2","0.6.32~rc+dfsg-1ubuntu2.3"],"ecosystem_specific":{"binaries":[{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1","binary_name":"avahi-autoipd"},{"binary_name":"avahi-daemon","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"avahi-discover","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"avahi-dnsconfd","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1","binary_name":"avahi-ui-utils"},{"binary_name":"avahi-utils","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-client3","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-common-data","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1","binary_name":"libavahi-common3"},{"binary_name":"libavahi-compat-libdnssd1","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-core7","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-glib1","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-gobject0","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-qt4-1","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-ui-gtk3-0","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"libavahi-ui0","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"},{"binary_name":"python-avahi","binary_version":"0.6.32~rc+dfsg-1ubuntu2.3+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3468.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/avahi@0.7-3.1ubuntu1.3?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.7-3.1ubuntu1.3"}]}],"versions":["0.6.32-1ubuntu1","0.7-3ubuntu1","0.7-3ubuntu2","0.7-3.1ubuntu1","0.7-3.1ubuntu1.1","0.7-3.1ubuntu1.2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.7-3.1ubuntu1.3","binary_name":"avahi-autoipd"},{"binary_name":"avahi-daemon","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"avahi-discover","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"avahi-dnsconfd","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"avahi-ui-utils","binary_version":"0.7-3.1ubuntu1.3"},{"binary_version":"0.7-3.1ubuntu1.3","binary_name":"avahi-utils"},{"binary_name":"gir1.2-avahi-0.6","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"libavahi-client3","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"libavahi-common-data","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"libavahi-common3","binary_version":"0.7-3.1ubuntu1.3"},{"binary_version":"0.7-3.1ubuntu1.3","binary_name":"libavahi-compat-libdnssd1"},{"binary_name":"libavahi-core7","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"libavahi-glib1","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"libavahi-gobject0","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"libavahi-ui-gtk3-0","binary_version":"0.7-3.1ubuntu1.3"},{"binary_name":"python-avahi","binary_version":"0.7-3.1ubuntu1.3"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3468.json"}},{"package":{"name":"avahi","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/avahi@0.7-4ubuntu7.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.7-4ubuntu7.1"}]}],"versions":["0.7-4ubuntu5","0.7-4ubuntu6","0.7-4ubuntu7"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"avahi-autoipd","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"avahi-daemon","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"avahi-discover","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"avahi-dnsconfd","binary_version":"0.7-4ubuntu7.1"},{"binary_version":"0.7-4ubuntu7.1","binary_name":"avahi-ui-utils"},{"binary_name":"avahi-utils","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"gir1.2-avahi-0.6","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"libavahi-client3","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"libavahi-common-data","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"libavahi-common3","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"libavahi-compat-libdnssd1","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"libavahi-core7","binary_version":"0.7-4ubuntu7.1"},{"binary_version":"0.7-4ubuntu7.1","binary_name":"libavahi-glib1"},{"binary_name":"libavahi-gobject0","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"libavahi-ui-gtk3-0","binary_version":"0.7-4ubuntu7.1"},{"binary_name":"python-avahi","binary_version":"0.7-4ubuntu7.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3468.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}