{"id":"CVE-2021-25833","aliases":["EUVD-2021-12716","GHSA-f4rq-cvc9-g327"],"status":"published","title":"12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890","description":"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.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.43534,"percentile":0.98749,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-22","CWE-79"],"published":"2021-03-01T15:09:17Z","modified":"2026-10-24T02:46:41Z","products":[{"vendor":"onlyoffice","product":"document_server"}],"references":[{"url":"https://github.com/ONLYOFFICE/DocumentServer","tags":["x_refsource_MISC","x_transferred","Product","Vendor Advisory","package"]},{"url":"https://github.com/ONLYOFFICE/server","tags":["x_refsource_MISC","x_transferred","Product","package"]},{"url":"https://github.com/ONLYOFFICE/server/blob/v5.6.0.21/DocService/sources/converterservice.js#L200","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory"]},{"url":"https://github.com/ONLYOFFICE/server/blob/v5.6.0.21/FileConverter/sources/converter.js#L593","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory"]},{"url":"https://github.com/ONLYOFFICE/server/blob/v5.6.0.21/FileConverter/sources/converter.js#L283","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory"]},{"url":"https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25833","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-25833"},{"url":"https://github.com/advisories/GHSA-f4rq-cvc9-g327"}],"sources":{"cve":[{"id":"CVE-2021-25833","description":"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.","status":"published","published":"2021-03-01T15:09:17Z","modified":"2024-08-03T20:11:28.419Z","updated_at":"2026-11-02T14:32:59.802172Z"}],"euvd":[{"id":"EUVD-2021-12716","description":"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.","status":"published","published":"2021-03-01T15:09:17Z","modified":"2024-08-03T20:11:28Z","updated_at":"2026-11-03T03:24:52.420769Z"}],"ghsa":[{"id":"GHSA-f4rq-cvc9-g327","title":"12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890","description":"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.\r\n\r\nUPDATE!","status":"published","published":"2022-05-24T22:01:28Z","modified":"2023-01-30T05:05:13Z","cwes":["CWE-22","CWE-79"],"updated_at":"2026-11-02T14:47:13.441339Z"}],"nvd":[{"id":"CVE-2021-25833","description":"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.","status":"published","published":"2021-03-01T16:15:14.51Z","modified":"2026-06-17T03:42:29.673Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:06:50.399901Z"}],"osv":[{"id":"CVE-2021-25833","description":"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.","status":"published","published":"2021-03-01T16:15:14.51Z","modified":"2026-10-24T02:46:41.138742158Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:18.778776Z"}]}}