Is CVE-2021-20022 in the CISA KEV catalog?

Yes. CVE-2021-20022 is on the CISA Known Exploited Vulnerabilities list, added 2021-11-03, and has known ransomware campaign use.

What is the CVSS severity of CVE-2021-20022?

CVE-2021-20022 has a CVSS v3 base score of 7.2 (HIGH).

What is the EPSS score for CVE-2021-20022?

CVE-2021-20022 has an EPSS score of 16.51% (97th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-20022

HIGHCISA KEVEPSS 97th pctl

7.2

CVSS v3

NVD

Description

SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to upload an arbitrary file to the remote host.

CWE-434Unrestricted File Upload

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredHigh

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

16.51%probability of exploitation in 30 days

97thpercentile

Very high risk: more likely to be exploited than 97% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

SonicWall Email Security Unrestricted Upload of File Vulnerability

SonicWall Email Security contains an unrestricted upload of file with dangerous type vulnerability that allows a post-authenticated attacker to upload a file to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20021 and CVE-2021-20023 to achieve privilege escalation.

Apply updates per vendor instructions.

Remediation due: 2021-11-17

Associated with ransomware campaigns

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-10.