{"id":"CVE-2021-33500","details":"PuTTY before 0.75 on Windows allows remote servers to cause a denial of service (Windows GUI hang) by telling the PuTTY window to change its title repeatedly at high speed, which results in many SetWindowTextA or SetWindowTextW calls. NOTE: the same attack methodology may affect some OS-level GUIs on Linux or other platforms for similar reasons.","modified":"2026-03-15T14:41:26.131521Z","published":"2021-05-21T20:15:07.723Z","references":[{"type":"ADVISORY","url":"https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html"},{"type":"EVIDENCE","url":"https://docs.ssh-mitm.at/puttydos.html"},{"type":"EVIDENCE","url":"https://github.com/ssh-mitm/ssh-mitm-plugins/blob/main/ssh_mitm_plugins/ssh/putty_dos.py"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"fixed":"0.75"}]},{"events":[{"introduced":"0"},{"fixed":"0.75"}]}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-33500.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}