CVE-2021-30120 CRITICAL

CVE-2021-30120: 2FA bypass in Kaseya VSA <= v9.5.6

Vendor N/A
Product n/a
Published July 9, 2021
Last update August 3, 2024

CVSS base score

9.9/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Kaseya VSA before 9.5.7 allows attackers to bypass the 2FA requirement. The need to use 2FA for authentication in enforce client-side instead of server-side and can be bypassed using a local proxy. Thus rendering 2FA useless. Detailed description --- During the login process, after the user authenticates with username and password, the server sends a response to the client with the booleans MFARequired and MFAEnroled. If the attacker has obtained a password of a user and used an intercepting proxy (e.g. Burp Suite) to change the value of MFARequered from True to False, there is no prompt for the second factor, but the user is still logged in.

Key dates

02Disclosure timeline

July 9, 2021 CVE published
August 3, 2024 Record updated