{"id":"CVE-2023-28999","state":"PUBLISHED","title":"Nextcloud: Lack of authenticity of metadata keys allows a malicious server to gain access to E2EE folders","description":"Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files.​ This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.","publishedAt":"2023-04-04T12:51:08.241Z","updatedAt":"2025-02-11T16:32:05.176Z","severity":{"score":6.9,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["nextcloud security-advisories"],"affected":[{"vendor":"nextcloud","product":"security-advisories","versions":[{"version":">= 3.0.0, < 3.8.0","status":"affected"},{"version":">= 3.13.0, < 3.25.0","status":"affected"},{"version":">= 3.0.5, < 4.8.0","status":"affected"}]}],"references":["https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8875-wxww-3rr8","https://github.com/nextcloud/desktop/pull/5560","https://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_DanieleCoppola.pdf"],"weaknesses":["CWE-325"],"ingestedAt":"2026-10-29T20:05:52.290Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/28xxx/CVE-2023-28999.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2023-28999","state":"PUBLISHED","datePublished":"2023-04-04T12:51:08.241Z","dateUpdated":"2025-02-11T16:32:05.176Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2023-03-29T17:39:16.141Z"},"containers":{"cna":{"title":"Nextcloud: Lack of authenticity of metadata keys allows a malicious server to gain access to E2EE folders","descriptions":[{"lang":"en","value":"Nextcloud is an open-source productivity platform. 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