Vulnerability Description
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 Agent_Guid and AgentPassword This Agent_Guid 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Kaseya | Vsa Agent | < 9.5.0.24 |
| Kaseya | Vsa Server | < 9.5.7a |
Related Weaknesses (CWE)
References
- https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/Third Party Advisory
- https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/Third Party Advisory
- https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-JulVendor Advisory
- https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/ExploitThird Party Advisory
- https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/Third Party Advisory
- https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/Third Party Advisory
- https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-JulVendor Advisory
- https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/ExploitThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-US Government Resource
FAQ
What is CVE-2021-30116?
CVE-2021-30116 is a vulnerability with a CVSS score of 10.0 (CRITICAL). 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 downl...
How severe is CVE-2021-30116?
CVE-2021-30116 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-30116?
Check the references section above for vendor advisories and patch information. Affected products include: Kaseya Vsa Agent, Kaseya Vsa Server.