{"id":"UBUNTU-CVE-2020-14145","details":"The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client). NOTE: some reports state that 8.5 and 8.6 are also affected.","modified":"2026-02-01T04:42:46.508057Z","published":"2020-06-29T18:15:00Z","withdrawn":"2025-08-01T19:37:08Z","related":["USN-6279-1"],"upstream":["CVE-2020-14145"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-14145"},{"type":"REPORT","url":"https://www.fzi.de/en/news/news/detail-en/artikel/fsa-2020-2-ausnutzung-eines-informationslecks-fuer-gezielte-mitm-angriffe-auf-ssh-clients/"},{"type":"REPORT","url":"https://www.fzi.de/fileadmin/user_upload/2020-06-26-FSA-2020-2.pdf"},{"type":"REPORT","url":"https://github.com/openssh/openssh-portable/compare/V_8_3_P1...V_8_4_P1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6279-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-14145"}],"affected":[{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:6.6p1-2ubuntu2.13+esm2?arch=source&distro=esm-infra-legacy/trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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","1:6.6p1-2ubuntu2.13+esm2"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14145.json"}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:7.2p2-4ubuntu2.10+esm7?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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","1:7.2p2-4ubuntu2.10+esm4","1:7.2p2-4ubuntu2.10+esm5","1:7.2p2-4ubuntu2.10+esm6","1:7.2p2-4ubuntu2.10+esm7"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14145.json"}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:FIPS:16.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:7.2p2-4ubuntu2.fips.2.10.7?arch=source&distro=fips-updates/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:7.2p2-4ubuntu2.fips.2.2.3","1:7.2p2-4ubuntu2.fips.2.4.1","1:7.2p2-4ubuntu2.fips.2.4.2","1:7.2p2-4ubuntu2.fips.2.8.1","1:7.2p2-4ubuntu2.fips.2.10.1","1:7.2p2-4ubuntu2.fips.2.10.2","1:7.2p2-4ubuntu2.fips.2.10.3","1:7.2p2-4ubuntu2.fips.2.10.4","1:7.2p2-4ubuntu2.fips.2.10.5","1:7.2p2-4ubuntu2.fips.2.10.6","1:7.2p2-4ubuntu2.fips.2.10.7"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14145.json"}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:FIPS:16.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:7.2p2-4ubuntu2.fips.2.10.1?arch=source&distro=fips/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:7.2p2-4ubuntu2.fips.2.2","1:7.2p2-4ubuntu2.fips.2.2.1","1:7.2p2-4ubuntu2.fips.2.10.1"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14145.json"}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:7.6p1-4ubuntu0.7+esm4?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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","1:7.6p1-4ubuntu0.7+esm2","1:7.6p1-4ubuntu0.7+esm3","1:7.6p1-4ubuntu0.7+esm4"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14145.json"}},{"package":{"name":"openssh-ssh1","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/openssh-ssh1@1:7.5p1-10?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:7.5p1-8","1:7.5p1-9","1:7.5p1-9build1","1:7.5p1-10"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14145.json"}},{"package":{"name":"openssh","ecosystem":"Ubuntu:Pro:FIPS-updates:18.04:LTS","purl":"pkg:deb/ubuntu/openssh@1:7.9p1-10~ubuntu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