{"id":"CVE-2021-32802","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-32802","generatedAt":"2026-10-28T04:17:55.660Z","title":"There are several security concerns with passing user-generated content to this library, such as Server-Side-Request-Forgery, file disclosure or potentially executing code on the system.","description":"Nextcloud server is an open source, self hosted personal cloud. Nextcloud supports rendering image previews for user provided file content. For some image types, the Nextcloud server was invoking a third-party library that wasn't suited for untrusted user-supplied content. There are several security concerns with passing user-generated content to this library, such as Server-Side-Request-Forgery, file disclosure or potentially executing code on the system. The risk depends on your system configuration and the installed library version. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. These versions do not use this library anymore. As a workaround users may disable previews by setting `enable_previews` to `false` in `config.php`.","published":"2021-09-07T22:15:09.000Z","lastModified":"2026-06-17T03:53:39.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-829"],"affected":["nextcloud/nextcloud server"],"epss":{"score":0.02604,"percentile":0.85293,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://docs.nextcloud.com/server/21/admin_manual/configuration_files/previews_configuration.html#disabling-previews","tags":["Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-m682-v4g9-wrq7","tags":["Mitigation","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://hackerone.com/reports/1261413","tags":["Permissions Required","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://security.gentoo.org/glsa/202208-17","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://docs.nextcloud.com/server/21/admin_manual/configuration_files/previews_configuration.html#disabling-previews","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-m682-v4g9-wrq7","tags":["Mitigation","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hackerone.com/reports/1261413","tags":["Permissions Required","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202208-17","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-32802","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."}