{"id":"UBUNTU-CVE-2020-14002","details":"PuTTY 0.68 through 0.73 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).","modified":"2025-10-24T04:48:31Z","published":"2020-06-29T18:15:00Z","upstream":["CVE-2020-14002"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-14002"},{"type":"REPORT","url":"https://lists.tartarus.org/pipermail/putty-announce/"},{"type":"REPORT","url":"https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html"},{"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.cve.org/CVERecord?id=CVE-2020-14002"}],"affected":[{"package":{"name":"putty","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/putty@0.67-3+deb9u1build0.16.04.1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.65-2","0.66-1","0.66-2","0.66-3","0.66-4","0.67-1","0.67-2","0.67-3build0.16.04.1","0.67-3+deb9u1build0.16.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"pterm","binary_version":"0.67-3+deb9u1build0.16.04.1"},{"binary_name":"putty","binary_version":"0.67-3+deb9u1build0.16.04.1"},{"binary_name":"putty-tools","binary_version":"0.67-3+deb9u1build0.16.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14002.json"}},{"package":{"name":"putty","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/putty@0.70-4?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.70-1","0.70-2","0.70-3","0.70-4"],"ecosystem_specific":{"binaries":[{"binary_name":"pterm","binary_version":"0.70-4"},{"binary_name":"putty","binary_version":"0.70-4"},{"binary_name":"putty-tools","binary_version":"0.70-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14002.json"}},{"package":{"name":"putty","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/putty@0.73-2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.72-1","0.73-1","0.73-2"],"ecosystem_specific":{"binaries":[{"binary_name":"pterm","binary_version":"0.73-2"},{"binary_name":"putty","binary_version":"0.73-2"},{"binary_name":"putty-tools","binary_version":"0.73-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-14002.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}