Multiple Vulnerabilities in Kaseya VSA Could Allow for Arbitrary Code Execution

ITS Advisory Number: 
2021-085
Date(s) Issued: 
Tuesday, July 13, 2021
Subject: 
Multiple Vulnerabilities in Kaseya VSA Could Allow for Arbitrary Code Execution
Overview: 

Multiple vulnerabilities have been discovered in Kaseya VSA that could allow for arbitrary code execution. Kaseya VSA is a software used by MSPs to remotely manage networks and endpoints. Successful exploitation of these vulnerabilities could result in arbitrary code execution within the context of the application, an attacker gaining the same privileges as the logged-on user, or the bypassing of security restrictions. Depending on the permission associated with the application running the exploit, an attacker could then install programs; view, change, or delete data.

 

THREAT INTELLIGENCE:

It is reported that at least 50 direct Kaseya customers were impacted leading to between 800 to 1500 downstream businesses being exploited with these vulnerabilities.

 

Systems Affected: 
  • Kaseya VSA On-premises versions prior to 9.5.7a (9.5.7.2994)
RISK
GOVERNMENT
Large and medium government entities: 
High
Small government entities: 
Medium
BUSINESS
Large and medium business entities: 
High
Small business entities: 
Medium
Home Users: 
Low
Description: 

Multiple vulnerabilities have been discovered in Kaseya VSA that could allow for arbitrary code execution. These vulnerabilities can be exploited remotely if an attacker locates a vulnerable Kaseya Web interface. An attacker can exploit this issue to execute arbitrary code in the context of the running Kaseya server process. Details of these vulnerabilities are as follows:

 

Credentials leak and business logic flaw - CVE-2021-30116

XSS vulnerability - CVE-2021-30119

2FA bypass - CVE-2021-30120

 

Network IOCs

 

35.226.94[.]113

161.35.239[.]148

162.253.124[.]162

 

Endpoint IOCs

 



Web Log Indicators 

 

POST /dl.asp curl/7.69.1

GET /done.asp curl/7.69.1

POST /cgi-bin/KUpload.dll curl/7.69.1

GET /done.asp curl/7.69.1

POST /cgi-bin/KUpload.dll curl/7.69.1

POST /userFilterTableRpt.asp curl/7.69.1

 

Successful exploitation of these vulnerabilities could result in arbitrary code execution within the context of the application, an attacker gaining the same privileges as the logged-on user, or the bypassing of security restrictions. Depending on the permission associated with the application running the exploit, an attacker could then install programs; view, change, or delete data.

Actions: 
  • After appropriate testing, immediately apply appropriate updates and recommendations provided by Kaseya to vulnerable systems.
  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
  • Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources.
  • Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources.
  • Apply the Principle of Least Privilege to all systems and services.