{"id":"UBUNTU-CVE-2018-12551","details":"When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for authentication, any malformed data in the password file will be treated as valid. This typically means that the malformed data becomes a username and no password. If this occurs, clients can circumvent authentication and get access to the broker by using the malformed username. In particular, a blank line will be treated as a valid empty username. Other security measures are unaffected. Users who have only used the mosquitto_passwd utility to create and modify their password files are unaffected by this vulnerability.","modified":"2026-04-22T12:50:13.502957Z","published":"2019-03-27T18:29:00Z","upstream":["CVE-2018-12551"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-12551"},{"type":"REPORT","url":"https://mosquitto.org/blog/2019/02/version-1-5-6-released/"},{"type":"REPORT","url":"https://mosquitto.org/files/cve/2018-12551"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-12551"}],"affected":[{"package":{"name":"mosquitto","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/mosquitto@1.4.8-1ubuntu0.16.04.5?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.8-1ubuntu0.16.04.5"}]}],"versions":["1.4.3-1","1.4.4-1","1.4.7-1","1.4.8-1","1.4.8-1build1","1.4.8-1ubuntu0.16.04.1","1.4.8-1ubuntu0.16.04.2","1.4.8-1ubuntu0.16.04.3","1.4.8-1ubuntu0.16.04.4"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libmosquitto1","binary_version":"1.4.8-1ubuntu0.16.04.5"},{"binary_name":"libmosquittopp1","binary_version":"1.4.8-1ubuntu0.16.04.5"},{"binary_name":"mosquitto","binary_version":"1.4.8-1ubuntu0.16.04.5"},{"binary_name":"mosquitto-clients","binary_version":"1.4.8-1ubuntu0.16.04.5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-12551.json"}},{"package":{"name":"mosquitto","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/mosquitto@1.4.15-2ubuntu0.18.04.1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.15-2ubuntu0.18.04.1"}]}],"versions":["1.4.12-1","1.4.14-1","1.4.14-2","1.4.14-2build1","1.4.15-1","1.4.15-2"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libmosquitto1","binary_version":"1.4.15-2ubuntu0.18.04.1"},{"binary_name":"libmosquittopp1","binary_version":"1.4.15-2ubuntu0.18.04.1"},{"binary_name":"mosquitto","binary_version":"1.4.15-2ubuntu0.18.04.1"},{"binary_name":"mosquitto-clients","binary_version":"1.4.15-2ubuntu0.18.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-12551.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}