{"schema":"threatline.record/2","record":{"id":"CVE-2021-28799","aliases":[],"summary":"QNAP NAS Improper Authorization Vulnerability","details":"QNAP NAS running HBS 3 contains an improper authorization vulnerability which can allow remote attackers to log in to a device.","categories":["Network & edge"],"product":"Network Attached Storage (NAS)","vendor":"QNAP","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 3","vendor":"QNAP Systems Inc.","versions":[{"lessThan":"v16.0.0415","status":"affected","version":"unspecified","versionType":"custom"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 3","vendor":"QNAP Systems Inc.","versions":[{"lessThan":"v3.0.210412","status":"affected","version":"unspecified","versionType":"custom"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 3","vendor":"QNAP Systems Inc.","versions":[{"lessThan":"v3.0.210411","status":"affected","version":"unspecified","versionType":"custom"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 3","vendor":"QNAP Systems Inc.","versions":[{"lessThan":"v3.0.210411","status":"affected","version":"unspecified","versionType":"custom"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 3","vendor":"QNAP Systems Inc.","versions":[{"lessThan":"v16.0.0419","status":"affected","version":"unspecified","versionType":"custom"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 3","vendor":"QNAP Systems Inc.","versions":[{"lessThan":"v16.0.0419","status":"affected","version":"unspecified","versionType":"custom"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 2","vendor":"QNAP Systems Inc.","versions":[{"status":"unaffected","version":"all versions"}],"defaultStatus":null},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","source_modified_at":"2025-10-21T23:25:45.551Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"HBS 1.3","vendor":"QNAP Systems Inc.","versions":[{"status":"unaffected","version":"all versions"}],"defaultStatus":null}],"fixed_versions":[],"cvss":10,"severity":"Critical","kev":{"listed":true,"date_added":"2022-03-31","due_date":"2022-04-21","required_action":"Apply updates per vendor instructions.","ransomware_campaign_use":"Known"},"epss":{"probability":0.7825,"percentile":0.99581,"score_date":"2026-10-23"},"published_at":"2021-05-13T02:55:13.827Z","modified_at":"2025-10-21T23:25:45.551Z","provenance":[{"source":"CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T17:00:09.9001Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2021-28799","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2025-10-21T23:25:45.551Z"},{"source":"Nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-28799.yaml","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":null},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-28799","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","Nuclei","EPSS"],"references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-28799","source":"CISA KEV"},{"source":"CVE List","url":"https://www.qnap.com/en/security-advisory/QSA-21-13","tags":["x_refsource_MISC","x_transferred"]},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-28799","tags":["government-resource"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"active","automatable":"yes","technical_impact":"total","assessed_at":"2025-02-04T14:53:29.275519Z"},"exploits":[{"source":"Nuclei","kind":"Scanner template","name":"QNAP HBS 3 - 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