{"cve":{"cve_id":"CVE-2023-27992","is_kev":true,"kev_date_added":"2023-06-23","kev_vendor_project":"Zyxel","kev_product":"Multiple Network-Attached Storage (NAS) Devices","kev_vulnerability_name":"Zyxel Multiple NAS Devices Command Injection Vulnerability","kev_short_description":"Multiple Zyxel network-attached storage (NAS) devices contain a pre-authentication command injection vulnerability that could allow an unauthenticated attacker to execute commands remotely via a crafted HTTP request.","kev_required_action":"Apply updates per vendor instructions.","kev_due_date":"2023-07-14","kev_known_ransomware":false,"kev_notes":"https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products;  https://nvd.nist.gov/vuln/detail/CVE-2023-27992","kev_cwes":["CWE-78"],"epss_score":0.84265,"epss_percentile":0.99663,"epss_as_of":"2026-06-23","description":"The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.","published_at":"2023-06-19T11:42:41.774000Z","last_modified_at":null,"cvss_v3_score":9.8,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_v3_severity":"CRITICAL","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"active","ssvc_automatable":true,"ssvc_technical_impact":"total","cwes":["CWE-78"],"nvd_references":["https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products"],"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":"2026-06-24T00:09:31.350578Z","updated_at":"2026-06-29T01:28:55.728164Z"},"effective_severity":"CRITICAL","badges":["kev","epss"],"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":"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":"zyxel","vendor_name":"Zyxel","product_slug":"nas326-firmware","product_name":"NAS326 firmware","version_start":"< V5.21(AAZF.14)C0","version_start_inclusive":true,"version_end":"< V5.21(AAZF.14)C0","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:nas326-firmware:< V5.21(AAZF.14)C0:< V5.21(AAZF.14)C0"},{"vendor_slug":"zyxel","vendor_name":"Zyxel","product_slug":"nas540-firmware","product_name":"NAS540 firmware","version_start":"< V5.21(AATB.11)C0","version_start_inclusive":true,"version_end":"< V5.21(AATB.11)C0","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:nas540-firmware:< V5.21(AATB.11)C0:< V5.21(AATB.11)C0"},{"vendor_slug":"zyxel","vendor_name":"Zyxel","product_slug":"nas542-firmware","product_name":"NAS542 firmware","version_start":"< V5.21(ABAG.11)C0","version_start_inclusive":true,"version_end":"< V5.21(ABAG.11)C0","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:nas542-firmware:< V5.21(ABAG.11)C0:< V5.21(ABAG.11)C0"}],"exploit_refs":[],"news":[],"references":[{"url":"https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2023-06-19T11:42:41.774000Z","label":"CVE published","source":null},{"type":"cisa_reported","at":"2023-06-23T00:00:00Z","label":"Added to CISA KEV catalog","source":"kev"},{"type":"cvss_changed","at":"2026-06-28T17:27:27.289124Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:27:27.289124Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:27:27.289124Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"ssvc_changed","at":"2026-06-29T01:28:55.728164Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:28:55.728164Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:28:55.728164Z","label":"SSVC decision revised","source":"vulnrichment"}]}