Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.33, 8.x before 8.0.0.23, 9.0 before 9.0.0.19, and 9.1 before 9.1.0.9 does not properly require authentication, which allows remote attackers to bypass authentication and (1) add an administrative account via crafted request to LocalAuth/setAccount.aspx or (2) write to and execute arbitrary files via a full pathname in the PathData parameter to ConfigTab/uploader.aspx.

Directory traversal vulnerability in Kaseya Virtual System Administrator (VSA) 7.0.0.0 before 7.0.0.33, 8..0.0.0 before 8.0.0.23, 9.0.0.0 before 9.0.0.19, and 9.1.0.0 before 9.1.0.9 allows remote authenticated users to write to and execute arbitrary files due to insufficient restrictions in file paths to json.ashx.

An issue was discovered in Kaseya Virtual System Administrator (VSA) through 9.4.0.37. It has a critical information disclosure vulnerability. An unauthenticated attacker can send properly formatted requests to the web application and download sensitive files and information. For example, the /DATAREPORTS directory can be farmed for reports. Because this directory contains the results of reports such as NMAP, Patch Status, and Active Directory domain metadata, an attacker can easily collect this critical information and parse it for information. There are a number of directories affected.

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.

It is possible to exploit a Time of Check & Time of Use (TOCTOU) vulnerability by winning a race condition when Kaseya Virtual System Administrator agent 9.3.0.11 and earlier tries to execute its binaries from working and/or temporary folders. Successful exploitation results in the execution of arbitrary programs with "NT AUTHORITY\SYSTEM" privileges.

Directory traversal vulnerability in Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.29, 8.x before 8.0.0.18, 9.0 before 9.0.0.14, and 9.1 before 9.1.0.4 allows remote authenticated users to read arbitrary files via a crafted HTTP request.

Open redirect vulnerability in Kaseya Virtual System Administrator (VSA) 7.x before 7.0.0.29, 8.x before 8.0.0.18, 9.0 before 9.0.0.14, and 9.1 before 9.1.0.4 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via unspecified vectors.

kapfa.sys in Kaseya Virtual System Administrator (VSA) 6.5 before 6.5.0.17 and 7.0 before 7.0.0.16 allows local users to cause a denial of service (NULL pointer dereference and application crash) via unspecified vectors.