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CVE-2021-20021

Published: Apr 9, 2021Updated: Nov 10, 2025 Sources: CVE List NVD BDUCWE-269
9.8CRITICAL
NVD MITRE
EPSS Score
83.4%
Top 0.4%
CISA KEV
Active Exploitation
Since Nov 3, 2021
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Nuclei · OpenVAS

Description

A vulnerability in the SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-269

Affected Products

SonicWall
commercial·US
Email Security
Networking Infrastructure
email security appliance 9000 firmware
Networking Infrastructure
email security appliance 3300 firmware
Networking Infrastructure
email security appliance 4300 firmware
Networking Infrastructure
email security appliance 8300 firmware
Networking Infrastructure
email security appliance 5000 firmware
Networking Infrastructure
email security appliance 7000 firmware
Networking Infrastructure
email security appliance 5050 firmware
Networking Infrastructure
and 5 more affected products View all →

Exploitability

CISA Known Exploited Vulnerability
Added to KEV:Nov 3, 2021
Remediation due:Nov 17, 2021
Ransomware:Known ransomware use

Required action: Apply updates per vendor instructions.

Official Patch Available
Is your org exposed to CVE-2021-20021?We'll check your whole external perimeter for exposure — free. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique
Privilege Escalation
View detailed technique mapping

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0007
psirt.global.sonicwall.com
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20021
cisa.gov
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0007
psirt.global.sonicwall.com
and 2 more references View all →

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