What it is
CVE-2021-30120 is 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...
Vulnerability report
Exploited in the wild
High confidence
Not in CISA KEV
CVE-2021-30120
2FA bypass in Kaseya VSA <= v9.5.6
Kaseya / VSA
- Severity
- CVSS 9.9 · Critical
- Confidence
- High
- Exploit status
- Exploited in the wild
- EPSS
- 5.7%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is high.
Who is affected?
Kaseya / VSA.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Kaseya VSA before 9.5.7 allows attackers to bypass the 2FA requirement
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.
- Published
- 09 Jul 2021
- Exploitation Reported
- 14 Aug 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
CVE References
- csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure csirt.divd.nl · CVE Record https://csirt.divd.nl/2021/07/07/Kaseya-Limited-Disclosure/
- csrit.divd.nl/DIVD-2021-00011 csrit.divd.nl · CVE Record https://csrit.divd.nl/DIVD-2021-00011
- csrit.divd.nl/CVE-2021-30120 csrit.divd.nl · CVE Record https://csrit.divd.nl/CVE-2021-30120
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CVE
Independent exploitation attestation added to the KEV Intelligence record.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-08-14 04:30 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
9.9
Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS
5.7%
All CVSS Scores
CVSS v3.1
9.9
Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v2.0
5.0
Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N
Timeline
From disclosure to observed exploitation
-
Added to KEV Intelligence KEV Feed
High-confidence, third-party attested exploitation
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2021-30120
Free JSON includes basic KEV fields{
"cve_id": "CVE-2021-30120",
"confidence": "High",
"cvss_score": 9.9,
"epss_score": 0.05701,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
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