{"id":"USN-6279-1","summary":"openssh update","details":"It was discovered that OpenSSH has an observable discrepancy leading to an\ninformation leak in the algorithm negotiation. This update mitigates the\nissue by tweaking the client hostkey preference ordering algorithm to\nprefer the default ordering if the user has a key that matches the\nbest-preference default algorithm.\n","modified":"2026-05-20T16:06:08.737856650Z","published":"2023-08-09T06:08:18Z","references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6279-1"},{"type":"REPORT","url":"https://launchpad.net/bugs/2030275"}],"affected":[{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=trusty%2Fesm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.6p1-2ubuntu2.13+esm2"}]}],"versions":["1:6.2p2-6","1:6.2p2-6ubuntu1","1:6.4p1-1","1:6.4p1-2","1:6.5p1-1","1:6.5p1-2","1:6.5p1-3","1:6.5p1-4","1:6.5p1-6","1:6.6p1-1","1:6.6p1-2","1:6.6p1-2ubuntu1","1:6.6p1-2ubuntu2","1:6.6p1-2ubuntu2.2","1:6.6p1-2ubuntu2.3","1:6.6p1-2ubuntu2.4","1:6.6p1-2ubuntu2.6","1:6.6p1-2ubuntu2.7","1:6.6p1-2ubuntu2.8","1:6.6p1-2ubuntu2.10","1:6.6p1-2ubuntu2.11","1:6.6p1-2ubuntu2.12","1:6.6p1-2ubuntu2.13","1:6.6p1-2ubuntu2.13+esm1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"openssh-client","binary_version":"1:6.6p1-2ubuntu2.13+esm2"},{"binary_name":"openssh-server","binary_version":"1:6.6p1-2ubuntu2.13+esm2"},{"binary_name":"openssh-sftp-server","binary_version":"1:6.6p1-2ubuntu2.13+esm2"},{"binary_name":"ssh","binary_version":"1:6.6p1-2ubuntu2.13+esm2"},{"binary_name":"ssh-askpass-gnome","binary_version":"1:6.6p1-2ubuntu2.13+esm2"},{"binary_name":"ssh-krb5","binary_version":"1:6.6p1-2ubuntu2.13+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-6279-1.json","cves_map":{"cves":[],"ecosystem":"Ubuntu:Pro:14.04:LTS"}}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:7.2p2-4ubuntu2.10+esm4"}]}],"versions":["1:6.9p1-2","1:6.9p1-3","1:7.1p1-1","1:7.1p1-3","1:7.1p1-4","1:7.1p1-6","1:7.1p2-1","1:7.1p2-2","1:7.2p1-1","1:7.2p2-1","1:7.2p2-2","1:7.2p2-3","1:7.2p2-4","1:7.2p2-4ubuntu1","1:7.2p2-4ubuntu2.1","1:7.2p2-4ubuntu2.2","1:7.2p2-4ubuntu2.4","1:7.2p2-4ubuntu2.5","1:7.2p2-4ubuntu2.6","1:7.2p2-4ubuntu2.7","1:7.2p2-4ubuntu2.8","1:7.2p2-4ubuntu2.10","1:7.2p2-4ubuntu2.10+esm1","1:7.2p2-4ubuntu2.10+esm2","1:7.2p2-4ubuntu2.10+esm3"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"openssh-client","binary_version":"1:7.2p2-4ubuntu2.10+esm4"},{"binary_name":"ssh-askpass-gnome","binary_version":"1:7.2p2-4ubuntu2.10+esm4"},{"binary_name":"openssh-server","binary_version":"1:7.2p2-4ubuntu2.10+esm4"},{"binary_name":"openssh-client-ssh1","binary_version":"1:7.2p2-4ubuntu2.10+esm4"},{"binary_name":"ssh","binary_version":"1:7.2p2-4ubuntu2.10+esm4"},{"binary_name":"ssh-krb5","binary_version":"1:7.2p2-4ubuntu2.10+esm4"},{"binary_name":"openssh-sftp-server","binary_version":"1:7.2p2-4ubuntu2.10+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-6279-1.json","cves_map":{"cves":[],"ecosystem":"Ubuntu:Pro:16.04:LTS"}}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:7.6p1-4ubuntu0.7+esm2"}]}],"versions":["1:7.5p1-10","1:7.6p1-4","1:7.6p1-4ubuntu0.1","1:7.6p1-4ubuntu0.2","1:7.6p1-4ubuntu0.3","1:7.6p1-4ubuntu0.5","1:7.6p1-4ubuntu0.6","1:7.6p1-4ubuntu0.7","1:7.6p1-4ubuntu0.7+esm1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"openssh-client","binary_version":"1:7.6p1-4ubuntu0.7+esm2"},{"binary_name":"openssh-server","binary_version":"1:7.6p1-4ubuntu0.7+esm2"},{"binary_name":"openssh-sftp-server","binary_version":"1:7.6p1-4ubuntu0.7+esm2"},{"binary_name":"ssh","binary_version":"1:7.6p1-4ubuntu0.7+esm2"},{"binary_name":"ssh-askpass-gnome","binary_version":"1:7.6p1-4ubuntu0.7+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-6279-1.json","cves_map":{"cves":[],"ecosystem":"Ubuntu:Pro:18.04:LTS"}}},{"package":{"name":"openssh","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/openssh?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:8.2p1-4ubuntu0.9"}]}],"versions":["1:8.0p1-6build1","1:8.1p1-1","1:8.1p1-5","1:8.2p1-4","1:8.2p1-4ubuntu0.1","1:8.2p1-4ubuntu0.2","1:8.2p1-4ubuntu0.3","1:8.2p1-4ubuntu0.4","1:8.2p1-4ubuntu0.5","1:8.2p1-4ubuntu0.7","1:8.2p1-4ubuntu0.8"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"openssh-client","binary_version":"1:8.2p1-4ubuntu0.9"},{"binary_name":"openssh-server","binary_version":"1:8.2p1-4ubuntu0.9"},{"binary_name":"openssh-sftp-server","binary_version":"1:8.2p1-4ubuntu0.9"},{"binary_name":"openssh-tests","binary_version":"1:8.2p1-4ubuntu0.9"},{"binary_name":"ssh","binary_version":"1:8.2p1-4ubuntu0.9"},{"binary_name":"ssh-askpass-gnome","binary_version":"1:8.2p1-4ubuntu0.9"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-6279-1.json","cves_map":{"cves":[],"ecosystem":"Ubuntu:20.04:LTS"}}}],"schema_version":"1.7.5"}