{"id":"UBUNTU-CVE-2021-32728","details":"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.","modified":"2026-04-22T13:41:03.021930Z","published":"2021-08-18T16:15:00Z","upstream":["CVE-2021-32728"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-32728"},{"type":"REPORT","url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5"},{"type":"REPORT","url":"https://github.com/nextcloud/desktop/pull/3338"},{"type":"REPORT","url":"https://hackerone.com/reports/1189162"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-32728"}],"affected":[{"package":{"name":"nextcloud-desktop","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/nextcloud-desktop@2.6.2-1build1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.5.3-1","2.6.0-1","2.6.1-1","2.6.1-2","2.6.2-1","2.6.2-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.6.2-1build1","binary_name":"caja-nextcloud"},{"binary_name":"dolphin-nextcloud","binary_version":"2.6.2-1build1"},{"binary_version":"2.6.2-1build1","binary_name":"libnextcloudsync0"},{"binary_name":"nautilus-nextcloud","binary_version":"2.6.2-1build1"},{"binary_name":"nemo-nextcloud","binary_version":"2.6.2-1build1"},{"binary_name":"nextcloud-desktop","binary_version":"2.6.2-1build1"},{"binary_name":"nextcloud-desktop-cmd","binary_version":"2.6.2-1build1"},{"binary_name":"nextcloud-desktop-common","binary_version":"2.6.2-1build1"},{"binary_name":"nextcloud-desktop-l10n","binary_version":"2.6.2-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-32728.json"}},{"package":{"name":"nextcloud-desktop","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/nextcloud-desktop@3.4.2-1ubuntu1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.3-0ubuntu1","3.3.5-1","3.3.5-1ubuntu1","3.4.2-1","3.4.2-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"caja-nextcloud","binary_version":"3.4.2-1ubuntu1"},{"binary_name":"dolphin-nextcloud","binary_version":"3.4.2-1ubuntu1"},{"binary_name":"libnextcloudsync0","binary_version":"3.4.2-1ubuntu1"},{"binary_name":"nautilus-nextcloud","binary_version":"3.4.2-1ubuntu1"},{"binary_version":"3.4.2-1ubuntu1","binary_name":"nemo-nextcloud"},{"binary_name":"nextcloud-desktop","binary_version":"3.4.2-1ubuntu1"},{"binary_name":"nextcloud-desktop-cmd","binary_version":"3.4.2-1ubuntu1"},{"binary_name":"nextcloud-desktop-common","binary_version":"3.4.2-1ubuntu1"},{"binary_name":"nextcloud-desktop-l10n","binary_version":"3.4.2-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-32728.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}