{"id":"CVE-2021-32728","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-32728","generatedAt":"2026-10-27T23:29:43.257Z","title":"If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor.","description":"The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.","published":"2021-08-18T16:15:07.000Z","lastModified":"2026-06-17T03:53:31.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-295"],"affected":["nextcloud/desktop","debian/debian linux"],"epss":{"score":0.00851,"percentile":0.5795,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.85%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/nextcloud/desktop/pull/3338","tags":["Patch","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5","tags":["Exploit","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://hackerone.com/reports/1189162","tags":["Exploit","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://www.debian.org/security/2021/dsa-4974","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/nextcloud/desktop/pull/3338","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hackerone.com/reports/1189162","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2021/dsa-4974","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-32728","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}