An issue was discovered in Kaseya VSA RMM through 9.5.0.22. When using the default configuration, the LAN Cache feature creates a local account FSAdminxxxxxxxxx (e.g., FSAdmin123456789) on the server that hosts the LAN Cache and all clients that are assigned to a LAN Cache. This account is placed into the local Administrators group of all clients assigned to the LAN Cache. When the assigned client is a Domain Controller, the FSAdminxxxxxxxxx account is created as a domain account and automatically added as a member of the domain BUILTIN\Administrators group. Using the well known Pass-the-Hash techniques, an attacker can use the same FSAdminxxxxxxxxx hash from any LAN Cache client and pass this to a Domain Controller, providing administrative rights to the attacker on any Domain Controller. (Local account Pass-the-Hash mitigations do not protect domain accounts.)

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-14510
• https://lockstepgroup.com/blog/abusing-the-kaseya-lan-cache-fsadmin/
• https://lockstepgroup.com/blog/cve-2019-14510-abusing-the-kaseya-lan-cache-fsadmin-red-team-edition/
• https://www.kaseya.com/products/vsa/
• http://community.kaseya.com/xsp/f/355.aspx
• http://community.kaseya.com/xsp/f/355/t/24675.aspx