{"schema":"threatline.record/2","record":{"id":"CVE-2023-33009","aliases":[],"summary":"Zyxel Multiple Firewalls Buffer Overflow Vulnerability","details":"Zyxel ATP, USG FLEX, USG FLEX 50(W), USG20(W)-VPN, VPN, and ZyWALL/USG firewalls contain a buffer overflow vulnerability in the notification function that could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and remote code execution on an affected device.","categories":["Network & edge"],"product":"Multiple Firewalls","vendor":"Zyxel","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-33009","source_modified_at":"2025-10-21T23:05:47.636Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"ATP series firmware","vendor":"Zyxel","versions":[{"status":"affected","version":"4.60 through 5.36 Patch 1"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-33009","source_modified_at":"2025-10-21T23:05:47.636Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"USG FLEX series firmware","vendor":"Zyxel","versions":[{"status":"affected","version":"4.60 through 5.36 Patch 1"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-33009","source_modified_at":"2025-10-21T23:05:47.636Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"USG FLEX 50(W) firmware","vendor":"Zyxel","versions":[{"status":"affected","version":"4.60 through 5.36 Patch 1"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-33009","source_modified_at":"2025-10-21T23:05:47.636Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"USG20(W)-VPN firmware","vendor":"Zyxel","versions":[{"status":"affected","version":"4.60 through 5.36 Patch 1"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-33009","source_modified_at":"2025-10-21T23:05:47.636Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"VPN series firmware","vendor":"Zyxel","versions":[{"status":"affected","version":"4.60 through 5.36 Patch 1"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-33009","source_modified_at":"2025-10-21T23:05:47.636Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"ZyWALL/USG series firmware","vendor":"Zyxel","versions":[{"status":"affected","version":"4.60 through 4.73 Patch 1"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":9.8,"severity":"Critical","kev":{"listed":true,"date_added":"2023-06-05","due_date":"2023-06-26","required_action":"Apply updates per vendor instructions.","ransomware_campaign_use":"Unknown"},"epss":{"probability":0.28144,"percentile":0.98112,"score_date":"2026-10-23"},"published_at":"2023-05-24T00:00:00.000Z","modified_at":"2025-10-21T23:05:47.636Z","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-2023-33009","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2025-10-21T23:05:47.636Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2023-33009","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls","tags":["x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-33009","source":"CISA KEV"},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-33009","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":"2025-02-04T16:14:56.233928Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2025-10-21T23:05:47.636Z","content_hash":"71c567424854dc951deb3c973b57c2c186b9e89863756a123d915476abb3d537"}}