{"id":"UBUNTU-CVE-2021-28166","details":"In Eclipse Mosquitto version 2.0.0 to 2.0.9, if an authenticated client that had connected with MQTT v5 sent a crafted CONNACK message to the broker, a NULL pointer dereference would occur.","modified":"2025-07-16T08:26:16.591542Z","published":"2021-04-07T19:15:00Z","withdrawn":"2025-07-18T16:46:43Z","upstream":["CVE-2021-28166"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-28166"},{"type":"REPORT","url":"https://bugs.eclipse.org/bugs/show_bug.cgi?id=572608"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-28166"}],"affected":[{"package":{"name":"mosquitto","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/mosquitto@2.0.11-1ubuntu1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.11-1ubuntu1"}]}],"versions":["2.0.11-1","2.0.11-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.0.11-1ubuntu1","binary_name":"libmosquitto-dev"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"libmosquitto1"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"libmosquitto1-dbgsym"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"libmosquittopp-dev"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"libmosquittopp1"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"libmosquittopp1-dbgsym"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"mosquitto"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"mosquitto-clients"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"mosquitto-clients-dbgsym"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"mosquitto-dbgsym"},{"binary_version":"2.0.11-1ubuntu1","binary_name":"mosquitto-dev"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28166.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}