{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2021-33500","sourceIdentifier":"cve@mitre.org","published":"2021-05-21T20:15:07.723","lastModified":"2026-06-17T03:54:41.047","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"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."},{"lang":"es","value":"PuTTY versiones anteriores a 0.75, en Windows permite a servidores remotos causar una denegación de servicio (colgar la GUI de Windows) al indicar a la ventana de PuTTY que cambie su título repetidamente a gran velocidad, lo que resulta en muchas llamadas a SetWindowTextA o SetWindowTextW. NOTA: la misma metodología de ataque puede afectar a algunas interfaces gráficas de usuario en Linux y otras plataformas por razones similares"}],"affected":[{"source":"cve@mitre.org","affectedData":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"cve@mitre.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"cvssMetricV2":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P","baseScore":5.0,"accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL"},"baseSeverity":"MEDIUM","exploitabilityScore":10.0,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"NVD-CWE-noinfo"}]}],"configurations":[{"operator":"AND","nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:putty:putty:*:*:*:*:*:*:*:*","versionEndExcluding":"0.75","matchCriteriaId":"1C69E11C-8272-4BBA-924C-1EC3A3FA01CA"}]},{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":false,"criteria":"cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*","matchCriteriaId":"A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}],"references":[{"url":"https://docs.ssh-mitm.at/puttydos.html","source":"cve@mitre.org","tags":["Exploit","Third Party Advisory"]},{"url":"https://github.com/ssh-mitm/ssh-mitm-plugins/blob/main/ssh_mitm_plugins/ssh/putty_dos.py","source":"cve@mitre.org","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html","source":"cve@mitre.org","tags":["Release Notes","Third Party Advisory"]},{"url":"https://docs.ssh-mitm.at/puttydos.html","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Exploit","Third Party Advisory"]},{"url":"https://github.com/ssh-mitm/ssh-mitm-plugins/blob/main/ssh_mitm_plugins/ssh/putty_dos.py","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Release Notes","Third Party Advisory"]}]}}