{"cve":{"cve_id":"CVE-2021-35029","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":0.02255,"epss_percentile":0.80672,"epss_as_of":"2026-06-23","description":"An authentication bypasss vulnerability in the web-based management interface of Zyxel USG/Zywall series firmware versions 4.35 through 4.64 and USG Flex, ATP, and VPN series firmware versions 4.35 through 5.01, which could allow a remote attacker to execute arbitrary commands on an affected device.","published_at":"2021-07-02T10:29:07Z","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":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-287"],"nvd_references":["https://www.zyxel.com/support/Zyxel_security_advisory_for_attacks_against_security_appliances.shtml"],"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":"2026-06-28T23:15:49.644234Z"},"effective_severity":"CRITICAL","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":"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":"atp-series-firmware","product_name":"ATP series firmware","version_start":"4.35 through 5.01","version_start_inclusive":true,"version_end":"4.35 through 5.01","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:atp-series-firmware:4.35 through 5.01:4.35 through 5.01"},{"vendor_slug":"zyxel","vendor_name":"Zyxel","product_slug":"usg-flex-series-firmware","product_name":"USG FLEX series firmware","version_start":"4.35 through 5.01","version_start_inclusive":true,"version_end":"4.35 through 5.01","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:usg-flex-series-firmware:4.35 through 5.01:4.35 through 5.01"},{"vendor_slug":"zyxel","vendor_name":"Zyxel","product_slug":"usg-zywall-series-firmware","product_name":"USG/ZyWALL series firmware","version_start":"4.35 through 4.64","version_start_inclusive":true,"version_end":"4.35 through 4.64","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:usg-zywall-series-firmware:4.35 through 4.64:4.35 through 4.64"},{"vendor_slug":"zyxel","vendor_name":"Zyxel","product_slug":"vpn-series-firmware","product_name":"VPN series firmware","version_start":"4.35 through 5.01","version_start_inclusive":true,"version_end":"4.35 through 5.01","version_end_inclusive":true,"cpe23_uri":"cve5:zyxel:vpn-series-firmware:4.35 through 5.01:4.35 through 5.01"}],"exploit_refs":[],"news":[],"references":[{"url":"https://www.zyxel.com/support/Zyxel_security_advisory_for_attacks_against_security_appliances.shtml","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2021-07-02T10:29:07Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:18:49.906573Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:18:49.906573Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:18:49.906573Z","label":"CVSS score revised","source":"cvelistv5"}]}