PatchTheCVECVE-2021-30116: Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerability
CVE-2021-30116 is a critical-severity flaw (CVSS 10.0) affecting vsa agent, vsa server, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 A
Why this priority
- Critical severity
- EPSS top 1%: very likely to be exploited
- Exploited in the wild (CISA KEV)
- Used in ransomware campaigns
- Public exploit reference
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 10.0 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 85.7% (top 1%) |
| CISA exploited list | Yes, fix due 2021-11-17, used in ransomware |
| Weakness | CWE-522 |
| Published | 2021-07-09 |
| Last modified | 2026-08-14 |
Last updated 2026-08-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Exploited Added to the CISA Known Exploited Vulnerabilities list
- Deadline CISA due date for US federal agencies to patch
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- Write-up: helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-July-2nd-2021
- Nuclei scan template: Kaseya VSA < 9.5.7 - Credential Disclosure via Windows Agent
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-30116?
vsa agent: upgrade to 9.5.0.24; vsa server: upgrade to 9.5.7a. Exact commands for each OS are on this page.
Is CVE-2021-30116 being exploited?
Yes. CVE-2021-30116 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.
What does CVE-2021-30116 affect?
CVE-2021-30116 affects vsa agent, vsa server. Severity is critical (CVSS 10.0). 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
How urgent is CVE-2021-30116?
Priority 100/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action