CVE-2021-30116
랜섬웨어 악용 Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerability
악용 여부
랜섬웨어 악용
심각도 (발행처 발표값)
심각9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
악용 확률 (EPSS)
85.7%
한국어 공식 권고
CISA 원문
Kaseya Virtual System/Server Administrator (VSA) contains an information disclosure vulnerability allowing an attacker to obtain the sessionId that can be used to execute further attacks against the system.— CISA KEV · shortDescription 원문
Apply updates per vendor instructions.— CISA KEV · requiredAction 원문
취약점 설명 (NVD 원문)
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.
CWE-522 CWE-522
악용 확률 변화
| 기준일 | 확률 | 백분위 |
|---|---|---|
| 2026-09-06 | 85.73% | 99.7% |
| 2026-09-05 | 85.73% | 99.7% |
| 2026-09-04 | 85.73% | 99.7% |