An unrestricted file upload vulnerability exists in Kaseya KServer versions prior to 6.3.0.2. The uploadImage.asp endpoint allows unauthenticated users to upload files to arbitrary paths via a crafted filename parameter in a multipart/form-data POST request. Due to the lack of authentication and input sanitation, an attacker can upload a file with an .asp extension to a web-accessible directory, which can then be invoked to execute arbitrary code with the privileges of the IUSR account. The vulnerability enables remote code execution without prior authentication and was resolved in version 6.3.0.2 by removing the vulnerable uploadImage.asp endpoint.

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.

ConnectWise ManagedITSync integration through 2017 for Kaseya VSA is vulnerable to unauthenticated remote commands that allow full direct access to the Kaseya VSA database. In February 2019, attackers have actively exploited this in the wild to download and execute ransomware payloads on all endpoints managed by the VSA server. If the ManagedIT.asmx page is available via the Kaseya VSA web interface, anyone with access to the page is able to run arbitrary SQL queries, both read and write, without authentication.

Kaseya VSA RMM before R9.3 9.3.0.35, R9.4 before 9.4.0.36, and R9.5 before 9.5.0.5 allows unprivileged remote attackers to execute PowerShell payloads on all managed devices. In January 2018, attackers actively exploited this vulnerability in the wild.