CVE-2021-20022

HIGH
7.2
CVSS Score
Published: April 9, 2021 at 05:50 PM UTC
Updated: October 1, 2026 at 09:17 PM UTC
19 products affected across 1 vendorEmail SecurityEmail Security Appliance 7050 FirmwareEmail Security Appliance 5000 Firmware· also runs on 1 platform

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Severity
HIGH7.2
Exploitation
CISA KEV
Exploit prediction
EPSS 17%
SSVC
Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score16.6%

EPSS (Exploit Prediction Scoring System) estimates a 16.6% chance this CVE is exploited in the wild within the next 30 days — higher than 97% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

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.

Required Action
Apply updates per vendor instructions.
Ransomware Use
Known
Added to KEV
Nov 3, 2021
Remediation Due
Nov 17, 2021
1804 days overdue

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 10.0.9v < 10.0.9.6103
Affected range stops below 10.0.9.6103, so it looks safe — our inference, not a vendor statement
microsoft-windows (environment)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-3300 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-4300 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-5000 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-5050 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-7000 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-7050 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-8300 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement
sonicwall-email-security-appliance-9000 (same device)
v < 10.0.9.6105
Affected range stops below 10.0.9.6105, so it looks safe — our inference, not a vendor statement

Runs on — not affected

The affected product only carries this flaw when running on these platforms. The platforms themselves are not vulnerable.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

SSVC — Action Prioritization

SSVCActiveAutomatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.2HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-434

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