CVE-2021-30116 — Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerab

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

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2021-11-03. Ransomware use: Known.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2021-07-09T00:00:00.000Z
• Last modified: 2025-10-21T23:25:41.692Z
• Added to CISA KEV: 2021-11-03
• BOD 22-01 due: 2021-11-17

09References

• csirt.divd.nl — https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/
• helpdesk.kaseya.com — https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-Jul…
• csirt.divd.nl — https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/
• www.secpod.com — https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/