CVE-2021-30116: Unauthenticated credential leak and business logic flaw in Kaseya VSA <= v9.5.6
In CISA’s Known Exploited Vulnerabilities catalog: Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerability.
Added , federal remediation due . Known ransomware use: Known.
Required action: Apply updates per vendor instructions.
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
Kaseya: Virtual System/Server Administrator (VSA)
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/ (opens in new tab)
- csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/ (opens in new tab)
- helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-July-2nd-2021 (opens in new tab)
- www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/ (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)