CVE-2021-30120: 2FA bypass in Kaseya VSA <= v9.5.6
- Is it exploited?
Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of .
VulnCheck KEV lists it since . It cites 7 public reports, the first from .
- How likely is exploitation in the next 30 days?
- 5.7%
EPSS score, percentile 93 of all scored records. A probability estimated by FIRST, not a report of exploitation.
CISA's SSVC assessment in the CVE record lists exploitation as active.
- How severe?
- 9.9 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
Upgrade to a version above 9.5.6Solution from the CVE record.
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.
Source: CISA KEV 2026.10.29, as of ; VulnCheck KEV, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
Description
2FA bypass in Kaseya VSA <= v9.5.6
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.
Source: CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.
Source: CVE List, as of . About the data.
Timeline
| Date | Event |
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| CVE record published | |
| CVE record last updated |