CVE-2021-30116

KEV
Published: Lug 09, 2021 Last Modified: Nov 10, 2025
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 10,0
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: changed
Confidentiality: high
Integrity: high
Availability: high
HIGH 7,5
Access Vector: network
Access Complexity: low
Authentication: none
Confidentiality: partial
Integrity: partial
Availability: partial

Description

AI Translation Available

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.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,4984
Percentile
1,0th
Updated

EPSS Score Trend (Last 90 Days)

522

Insufficiently Protected Credentials

Incomplete
Common Consequences
Security Scopes Affected:
Access Control
Potential Impacts:
Gain Privileges Or Assume Identity
Applicable Platforms
Technologies: ICS/OT, Not Technology-Specific, Web Based
View CWE Details
Application

Vsa Server by Kaseya

Version Range Affected
To 9.5.7a (exclusive)
cpe:2.3:a:kaseya:vsa_server:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Vsa Agent by Kaseya

Version Range Affected
To 9.5.0.24 (exclusive)
cpe:2.3:a:kaseya:vsa_agent:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021…
https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/
https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/
https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-Ju…
https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/
https://csirt.divd.nl/2021/07/04/Kaseya-Case-Update-2/
https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/
https://helpdesk.kaseya.com/hc/en-gb/articles/4403440684689-Important-Notice-Ju…
https://www.secpod.com/blog/kaseya-vsa-zero-day-by-revil/