{
    "id": "CVE-2021-30116",
    "published": "2021-07-09 14:15:07",
    "last_modified": "2026-08-14 05:16:54",
    "cvss_score": "10.0",
    "cvss_severity": "CRITICAL",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
    "cwe": "CWE-522",
    "description": "Kaseya VSA before 9.5.7 allows credential disclosure, as exploited in the wild in July 2021. By default Kaseya VSA on premise offers a download page where the clients for the installation can be downloaded. The default URL for this page is https://x.x.x.x/dl.asp When an attacker download a client for Windows and installs it, the file KaseyaD.ini is generated (C:\\Program Files (x86)\\Kaseya\\XXXXXXXXXX\\KaseyaD.ini) which contains an Agent_Guid and AgentPassword This Agent_Guid and AgentPassword can be used to log in on dl.asp (https://x.x.x.x/dl.asp?un=840997037507813&pw=113cc622839a4077a84837485ced6b93e440bf66d44057713cb2f95e503a06d9) This request authenticates the client and returns a sessionId cookie that can be used in subsequent attacks to bypass authentication. Security issues discovered --- * Unauthenticated download page leaks credentials * Credentials of agent software can be used to obtain a sessionId (cookie) that can be used for services not intended for use by agents * dl.asp accepts credentials via a GET request * Access to KaseyaD.ini gives an attacker access to sufficient information to penetrate the Kaseya installation and its clients. Impact --- Via the page /dl.asp enough information can be obtained to give an attacker a sessionId that can be used to execute further (semi-authenticated) attacks against the system.",
    "epss_score": "0.85735",
    "epss_percentile": "0.99720",
    "kev": 1,
    "kev_due": "2021-11-17",
    "has_exploit": 0,
    "updated_at": "2026-09-26 18:27:47",
    "priority": {
        "rank": 1,
        "label": "Patch first",
        "why": "On CISA KEV — known exploited in the wild, due 2021-11-17."
    },
    "products": [
        {
            "vendor": "kaseya",
            "product": "vsa_agent"
        },
        {
            "vendor": "kaseya",
            "product": "vsa_server"
        }
    ],
    "kev_detail": {
        "cve_id": "CVE-2021-30116",
        "date_added": "2021-11-03",
        "due_date": "2021-11-17",
        "vendor": "Kaseya",
        "product": "Virtual System/Server Administrator (VSA)",
        "name": "Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerability",
        "ransomware": 1
    },
    "exploits": [],
    "refs_list": [
        "https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/",
        "https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/",
        "https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-July-2nd-2021",
        "https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/",
        "https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/",
        "https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/",
        "https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-July-2nd-2021",
        "https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/",
        "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30116"
    ]
}