{"cve":{"cve_id":"CVE-2021-28798","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00938,"epss_percentile":0.56221,"epss_as_of":"2026-06-23","description":"A relative path traversal vulnerability has been reported to affect QNAP NAS running QTS and QuTS hero. If exploited, this vulnerability allows attackers to modify files that impact system integrity. QNAP have already fixed this vulnerability in the following versions: QTS 4.5.2.1630 Build 20210406 and later QTS 4.3.6.1663 Build 20210504 and later QTS 4.3.3.1624 Build 20210416 and later QuTS hero h4.5.2.1638 Build 20210414 and later QNAP NAS running QTS 4.5.3 are not affected.","published_at":"2021-05-21T03:00:11.671000Z","last_modified_at":null,"cvss_v3_score":8.8,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-284","CWE-23"],"nvd_references":["https://www.qnap.com/zh-tw/security-advisory/qsa-21-14"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:15:26.101164Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"qts","product_name":"QTS","version_start":"unspecified","version_start_inclusive":true,"version_end":"4.5.2.1630 Build 20210406","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:qts:unspecified:4.5.2.1630 Build 20210406"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"qts","product_name":"QTS","version_start":"unspecified","version_start_inclusive":true,"version_end":"4.3.6.1663 Build 20210504","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:qts:unspecified:4.3.6.1663 Build 20210504"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"qts","product_name":"QTS","version_start":"unspecified","version_start_inclusive":true,"version_end":"4.3.3.1624 Build 20210416","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:qts:unspecified:4.3.3.1624 Build 20210416"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"qts","product_name":"QTS","version_start":"4.5.3","version_start_inclusive":true,"version_end":"4.5.3","version_end_inclusive":true,"cpe23_uri":"cve5:qnap-systems-inc.:qts:4.5.3:4.5.3"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"quts-hero","product_name":"QuTS hero","version_start":"unspecified","version_start_inclusive":true,"version_end":"h4.5.2.1638 Build 20210414","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:quts-hero:unspecified:h4.5.2.1638 Build 20210414"}],"exploit_refs":[],"news":[],"references":[{"url":"https://www.qnap.com/zh-tw/security-advisory/qsa-21-14","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2021-05-21T03:00:11.671000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:18:04.076611Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:18:04.076611Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:18:04.076611Z","label":"CVSS score revised","source":"cvelistv5"}]}