{"id":"UBUNTU-CVE-2020-28049","details":"An issue was discovered in SDDM before 0.19.0. It incorrectly starts the X server in a way that - for a short time period - allows local unprivileged users to create a connection to the X server without providing proper authentication. A local attacker can thus access X server display contents and, for example, intercept keystrokes or access the clipboard. This is caused by a race condition during Xauthority file creation.","modified":"2025-10-24T04:48:53Z","published":"2020-11-04T19:15:00Z","upstream":["CVE-2020-28049"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-28049"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2020/11/04/2"},{"type":"REPORT","url":"https://github.com/sddm/sddm/commit/be202f533ab98a684c6a007e8d5b4357846bc222"},{"type":"REPORT","url":"https://bugzilla.suse.com/show_bug.cgi?id=1177201"},{"type":"REPORT","url":"https://bugzilla.suse.com/show_bug.cgi?id=CVE-2020-28049"},{"type":"REPORT","url":"https://github.com/sddm/sddm/blob/v0.19.0/ChangeLog"},{"type":"REPORT","url":"https://github.com/sddm/sddm/releases"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-28049"}],"affected":[{"package":{"name":"sddm","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/sddm@0.13.0-1ubuntu5?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.11.0-0ubuntu11","0.11.0-0ubuntu12","0.13.0-1ubuntu1","0.13.0-1ubuntu3","0.13.0-1ubuntu4","0.13.0-1ubuntu5"],"ecosystem_specific":{"binaries":[{"binary_version":"0.13.0-1ubuntu5","binary_name":"sddm"},{"binary_version":"0.13.0-1ubuntu5","binary_name":"sddm-theme-circles"},{"binary_version":"0.13.0-1ubuntu5","binary_name":"sddm-theme-elarun"},{"binary_version":"0.13.0-1ubuntu5","binary_name":"sddm-theme-maldives"},{"binary_version":"0.13.0-1ubuntu5","binary_name":"sddm-theme-maui"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-28049.json"}},{"package":{"name":"sddm","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/sddm@0.17.0-1ubuntu7?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.14.0-4ubuntu1","0.14.0-4ubuntu2","0.17.0-1ubuntu1","0.17.0-1ubuntu2","0.17.0-1ubuntu3","0.17.0-1ubuntu4","0.17.0-1ubuntu5","0.17.0-1ubuntu6","0.17.0-1ubuntu7"],"ecosystem_specific":{"binaries":[{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm"},{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm-theme-debian-elarun"},{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm-theme-debian-maui"},{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm-theme-elarun"},{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm-theme-maldives"},{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm-theme-maui"},{"binary_version":"0.17.0-1ubuntu7","binary_name":"sddm-theme-maya"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-28049.json"}},{"package":{"name":"sddm","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/sddm@0.18.1-1ubuntu2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.18.0-1ubuntu2","0.18.1-1ubuntu1","0.18.1-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm"},{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm-theme-debian-elarun"},{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm-theme-debian-maui"},{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm-theme-elarun"},{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm-theme-maldives"},{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm-theme-maui"},{"binary_version":"0.18.1-1ubuntu2","binary_name":"sddm-theme-maya"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-28049.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"low"}]}