CVE-2021-30116

CVE Enrichment

CVSS: 9.8 CRITICAL
EPSS: 85.74%
EPSS Percentile: 99.72%
CISA KEV: YES — Known Exploited 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.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: cve@mitre.org
Published: 09-Jul-2021 21:15
Last Modified: 14-Aug-2026 12:16
EPSS Date: 2026-10-13
CWE: CWE-522

CVSS Vector


            CVSS:3.1                            AV:N /
                            AC:L /
                            PR:N /
                            UI:N /
                            S:U /
                            C:H /
                            I:H /
                            A:H

CISA KEV Details

Date Added: 2021-11-03
Remediation Due: 2021-11-17
Known Ransomware Campaign Use: Known
Required Action: Apply updates per vendor instructions.
Notes: https://nvd.nist.gov/vuln/detail/CVE-2021-30116

Affected Products / Versions

kaseya / vsa_agent
Version / affected range: * · before (exclusive) 9.5.0.24
cpe:2.3:a:kaseya:vsa_agent:*:*:*:*:*:*:*:*
kaseya / vsa_server
Version / affected range: * · before (exclusive) 9.5.7a
cpe:2.3:a:kaseya:vsa_server:*:*:*:*:*:*:*:*

References

Last enrichment sync: 13-Oct-2026 23:24
Sources: NVD · FIRST EPSS · CISA KEV
Latest successful provider update; providers refresh independently.

Reported Context (1)

ones that involved the REvil ransomware leveraging a vulnerability in the Kaseya VSA software (CVE-2021-30116) against managed service providers (MSPs) and their downstream customers. REvil, along with Vice Talos Q3 2021 Report: Ransomware Dominated Incident Response Engagements

Malware (11)

People (3)

Threat Actors (2)

MITRE ATT&CK (12)

Vendors (2)

Products (4)

Tools (8)

Industries (14)

Countries (1)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.