{
    "id": "CVE-2023-33009",
    "published": "2023-05-24 13:15:09",
    "last_modified": "2026-06-17 06:00:16",
    "cvss_score": "9.8",
    "cvss_severity": "CRITICAL",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
    "cwe": "CWE-120",
    "description": "A buffer overflow vulnerability in the notification function in Zyxel ATP series firmware versions 4.60 through 5.36 Patch 1, USG FLEX series firmware versions 4.60 through 5.36 Patch 1, USG FLEX 50(W) firmware versions 4.60 through 5.36 Patch 1, USG20(W)-VPN firmware versions 4.60 through 5.36 Patch 1, VPN series firmware versions 4.60 through 5.36 Patch 1, ZyWALL/USG series firmware versions 4.60 through 4.73 Patch 1, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and even a remote code execution on an affected device.",
    "epss_score": "0.28144",
    "epss_percentile": "0.98049",
    "kev": 1,
    "kev_due": "2023-06-26",
    "has_exploit": 0,
    "updated_at": "2026-09-26 18:31:48",
    "priority": {
        "rank": 1,
        "label": "Patch first",
        "why": "On CISA KEV — known exploited in the wild, due 2023-06-26."
    },
    "products": [
        {
            "vendor": "zyxel",
            "product": "atp100"
        },
        {
            "vendor": "zyxel",
            "product": "atp100_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "atp100w"
        },
        {
            "vendor": "zyxel",
            "product": "atp100w_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "atp200"
        },
        {
            "vendor": "zyxel",
            "product": "atp200_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "atp500"
        },
        {
            "vendor": "zyxel",
            "product": "atp500_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "atp700"
        },
        {
            "vendor": "zyxel",
            "product": "atp700_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "atp800"
        },
        {
            "vendor": "zyxel",
            "product": "atp800_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_20w-vpn"
        },
        {
            "vendor": "zyxel",
            "product": "usg_20w-vpn_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_40"
        },
        {
            "vendor": "zyxel",
            "product": "usg_40_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_100"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_100_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_100w"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_100w_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_200"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_200_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_50"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_50_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_500"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_500_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_50w"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_50w_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_700"
        },
        {
            "vendor": "zyxel",
            "product": "usg_flex_700_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "usg20-vpn"
        },
        {
            "vendor": "zyxel",
            "product": "usg20-vpn_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "vpn100"
        },
        {
            "vendor": "zyxel",
            "product": "vpn100_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "vpn1000"
        },
        {
            "vendor": "zyxel",
            "product": "vpn1000_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "vpn300"
        },
        {
            "vendor": "zyxel",
            "product": "vpn300_firmware"
        },
        {
            "vendor": "zyxel",
            "product": "vpn50"
        },
        {
            "vendor": "zyxel",
            "product": "vpn50_firmware"
        }
    ],
    "kev_detail": {
        "cve_id": "CVE-2023-33009",
        "date_added": "2023-06-05",
        "due_date": "2023-06-26",
        "vendor": "Zyxel",
        "product": "Multiple Firewalls",
        "name": "Zyxel Multiple Firewalls Buffer Overflow Vulnerability",
        "ransomware": 0
    },
    "exploits": [],
    "refs_list": [
        "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls",
        "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls",
        "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-33009"
    ]
}