{
    "id": "CVE-2021-20090",
    "published": "2021-04-29 15:15:10",
    "last_modified": "2026-06-17 03:33:15",
    "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-22",
    "description": "A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 could allow unauthenticated remote attackers to bypass authentication.",
    "epss_score": "0.99983",
    "epss_percentile": "0.99982",
    "kev": 1,
    "kev_due": "2021-11-17",
    "has_exploit": 0,
    "updated_at": "2026-09-26 18:27:28",
    "priority": {
        "rank": 1,
        "label": "Patch first",
        "why": "On CISA KEV — known exploited in the wild, due 2021-11-17."
    },
    "products": [
        {
            "vendor": "buffalo",
            "product": "wsr-2533dhp3-bk"
        },
        {
            "vendor": "buffalo",
            "product": "wsr-2533dhp3-bk_firmware"
        },
        {
            "vendor": "buffalo",
            "product": "wsr-2533dhpl2-bk"
        },
        {
            "vendor": "buffalo",
            "product": "wsr-2533dhpl2-bk_firmware"
        }
    ],
    "kev_detail": {
        "cve_id": "CVE-2021-20090",
        "date_added": "2021-11-03",
        "due_date": "2021-11-17",
        "vendor": "Arcadyan",
        "product": "Buffalo Firmware",
        "name": "Arcadyan Buffalo Firmware Path Traversal Vulnerability",
        "ransomware": 0
    },
    "exploits": [],
    "refs_list": [
        "https://www.kb.cert.org/vuls/id/914124",
        "https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/",
        "https://www.tenable.com/security/research/tra-2021-13",
        "https://www.kb.cert.org/vuls/id/914124",
        "https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/",
        "https://www.tenable.com/security/research/tra-2021-13",
        "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20090"
    ]
}