---
id: CVE-2021-30116
title: >-
  Kaseya VSA before 9.5.7 allows credential disclosure, as exploited in the wild
  in July 2021
summary: >-
  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 …
severity: critical
cvss: 10
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-522
  - CWE-522
vendor: kaseya
product: vsa_agent
affected:
  - vsa_agent < 9.5.0.24
  - vsa_server < 9.5.7a
patched:
  - vsa_agent 9.5.0.24
  - vsa_server 9.5.7a
published: '2021-07-09'
updated: '2026-08-14'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-30116'
references:
  - url: 'https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/'
    label: cve@mitre.org
  - url: 'https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/'
    label: cve@mitre.org
  - url: >-
      https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-July-2nd-2021
    label: cve@mitre.org
  - url: 'https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/'
    label: cve@mitre.org
  - url: 'https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-July-2nd-2021
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30116
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
  - exploit-available
epss: 0.85735
epssPercentile: 0.9972
kev: true
kevDateAdded: '2021-11-03'
kevDueDate: '2021-11-17'
kevRansomware: true
exploited: true
ingestedAt: '2026-08-14T06:15:27.569Z'
exploits:
  nuclei:
    - CVE-2021-30116
  checkedAt: '2026-09-25T08:20:38.529Z'
exploitAvailable: true
---

## Overview

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.

## Affected

- `vsa_agent < 9.5.0.24`
- `vsa_server < 9.5.7a`

## Remediation

Upgrade past the affected range:

- `vsa_agent 9.5.0.24`
- `vsa_server 9.5.7a`