Vulnerabilities > CVE-2015-6922 - Improper Authentication vulnerability in Kaseya Virtual System Administrator
Kaseya Virtual System Administrator (VSA) 7.x before 22.214.171.124, 8.x before 126.96.36.199, 9.0 before 188.8.131.52, and 9.1 before 184.108.40.206 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.
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Authentication Abuse An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
- Exploiting Trust in Client (aka Make the Client Invisible) An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
- Utilizing REST's Trust in the System Resource to Register Man in the Middle This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
- Man in the Middle Attack This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.
description Kaseya VSA uploader.aspx Arbitrary File Upload. CVE-2015-6922. Remote exploit for windows platform id EDB-ID:38401 last seen 2016-02-04 modified 2015-10-05 published 2015-10-05 reporter metasploit source https://www.exploit-db.com/download/38401/ title Kaseya VSA uploader.aspx Arbitrary File Upload description Kaseya Virtual System Administrator (VSA) 7.0 < 9.1 - Authenticated Arbitrary File Upload. CVE-2015-6589. Webapps exploit for ASP platform id EDB-ID:43882 last seen 2018-01-25 modified 2015-09-28 published 2015-09-28 reporter Exploit-DB source https://www.exploit-db.com/download/43882/ title Kaseya Virtual System Administrator (VSA) 7.0 < 9.1 - Authenticated Arbitrary File Upload description Kaseya Virtual System Administrator - Multiple Vulnerabilities. CVE-2015-6589,CVE-2015-6922,CVE-2015-6922. Webapps exploit for asp platform id EDB-ID:38351 last seen 2016-02-04 modified 2015-09-29 published 2015-09-29 reporter Pedro Ribeiro source https://www.exploit-db.com/download/38351/ title Kaseya Virtual System Administrator - Multiple Vulnerabilities
description This module exploits an arbitrary file upload vulnerability found in Kaseya VSA versions between 7 and 9.1. A malicious unauthenticated user can upload an ASP file to an arbitrary directory leading to arbitrary code execution with IUSR privileges. This module has been tested with Kaseya v220.127.116.11, v18.104.22.168 and v22.214.171.124. id MSF:EXPLOIT/WINDOWS/HTTP/KASEYA_UPLOADER last seen 2020-06-01 modified 2018-09-15 published 2015-09-29 references reporter Rapid7 source https://github.com/rapid7/metasploit-framework/blob/master//modules/exploits/windows/http/kaseya_uploader.rb title Kaseya VSA uploader.aspx Arbitrary File Upload description This module abuses the setAccount page on Kaseya VSA between 7 and 9.1 to create a new Master Administrator account. Normally this page is only accessible via the localhost interface, but the application does nothing to prevent this apart from attempting to force a redirect. This module has been tested with Kaseya VSA v126.96.36.199, v188.8.131.52 and v184.108.40.206. id MSF:AUXILIARY/ADMIN/HTTP/KASEYA_MASTER_ADMIN last seen 2020-06-04 modified 2018-09-15 published 2015-09-29 references reporter Rapid7 source https://github.com/rapid7/metasploit-framework/blob/master//modules/auxiliary/admin/http/kaseya_master_admin.rb title Kaseya VSA Master Administrator Account Creation
data source https://packetstormsecurity.com/files/download/133822/kaseya_uploader.rb.txt id PACKETSTORM:133822 last seen 2016-12-05 published 2015-10-02 reporter Pedro Ribeiro source https://packetstormsecurity.com/files/133822/Kaseya-VSA-uploader.aspx-Arbitrary-File-Upload.html title Kaseya VSA uploader.aspx Arbitrary File Upload data source https://packetstormsecurity.com/files/download/133782/kaseyavsa-execescalate.txt id PACKETSTORM:133782 last seen 2016-12-05 published 2015-09-30 reporter Pedro Ribeiro source https://packetstormsecurity.com/files/133782/Kaseya-Virtual-System-Administrator-Code-Execution-Privilege-Escalation.html title Kaseya Virtual System Administrator Code Execution / Privilege Escalation