{"id":"CVE-2021-25833","details":"A file extension handling issue was found in [server] module of ONLYOFFICE DocumentServer v4.2.0.71-v5.6.0.21. The file extension is controlled by an attacker through the request data and leads to arbitrary file overwriting. Using this vulnerability, a remote attacker can obtain remote code execution on DocumentServer.","modified":"2026-10-24T02:46:41.138742158Z","published":"2021-03-01T16:15:14.510Z","database_specific":{},"references":[{"type":"ADVISORY","url":"https://github.com/ONLYOFFICE/server/blob/v5.6.0.21/DocService/sources/converterservice.js#L200"},{"type":"ADVISORY","url":"https://github.com/ONLYOFFICE/server/blob/v5.6.0.21/FileConverter/sources/converter.js#L283"},{"type":"ADVISORY","url":"https://github.com/ONLYOFFICE/server/blob/v5.6.0.21/FileConverter/sources/converter.js#L593"},{"type":"PACKAGE","url":"https://github.com/ONLYOFFICE/DocumentServer"},{"type":"PACKAGE","url":"https://github.com/ONLYOFFICE/server"},{"type":"EVIDENCE","url":"https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25833"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/onlyoffice/server","events":[{"introduced":"761b989ff2a0b022ea2526bbd798d285150c3c54"},{"last_affected":"ec87c3fd5e9ed78e1711d473c9f7052883fd6f5b"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"4.2.0.71"},{"last_affected":"5.6.0.21"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:onlyoffice:document_server:*:*:*:*:*:*:*:*"}]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-25833.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}