{"cve":{"cve_id":"CVE-2021-38687","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":0.0128,"epss_percentile":0.66271,"epss_as_of":"2026-06-23","description":"A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of Surveillance Station: QTS 5.0.0 (64 bit): Surveillance Station 5.2.0.4.2 ( 2021/10/26 ) and later QTS 5.0.0 (32 bit): Surveillance Station 5.2.0.3.2 ( 2021/10/26 ) and later QTS 4.3.6 (64 bit): Surveillance Station 5.1.5.4.6 ( 2021/10/26 ) and later QTS 4.3.6 (32 bit): Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later QTS 4.3.3: Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later","published_at":"2021-12-29T13:05:14.828000Z","last_modified_at":null,"cvss_v3_score":8.1,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:H/PR:N/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-120"],"nvd_references":["https://www.qnap.com/en/security-advisory/qsa-21-46"],"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":"2026-06-28T23:16:02.253776Z"},"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":"H","value_label":"High"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"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":"surveillance-station","product_name":"Surveillance Station","version_start":"unspecified","version_start_inclusive":true,"version_end":"5.2.0.4.2 ( 2021/10/26 )","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:surveillance-station:unspecified:5.2.0.4.2 ( 2021/10/26 )"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"surveillance-station","product_name":"Surveillance Station","version_start":"unspecified","version_start_inclusive":true,"version_end":"5.2.0.3.2 ( 2021/10/26 )","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:surveillance-station:unspecified:5.2.0.3.2 ( 2021/10/26 )"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"surveillance-station","product_name":"Surveillance Station","version_start":"unspecified","version_start_inclusive":true,"version_end":"5.1.5.4.6 ( 2021/10/26 )","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:surveillance-station:unspecified:5.1.5.4.6 ( 2021/10/26 )"},{"vendor_slug":"qnap-systems-inc.","vendor_name":"QNAP Systems Inc.","product_slug":"surveillance-station","product_name":"Surveillance Station","version_start":"unspecified","version_start_inclusive":true,"version_end":"5.1.5.3.6 ( 2021/10/26 )","version_end_inclusive":false,"cpe23_uri":"cve5:qnap-systems-inc.:surveillance-station:unspecified:5.1.5.3.6 ( 2021/10/26 )"}],"exploit_refs":[],"news":[],"references":[{"url":"https://www.qnap.com/en/security-advisory/qsa-21-46","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2021-12-29T13:05:14.828000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:19:08.444434Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:19:08.444434Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:19:08.444434Z","label":"CVSS score revised","source":"cvelistv5"}]}