Is CVE-2021-20021 actively exploited?

CVE-2021-20021 has no public evidence of in-the-wild exploitation as of 2025-11-10.

What is the CVSS score for CVE-2021-20021?

CVE-2021-20021 has a CVSS score of 9.8 (CRITICAL severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2021-20021?

Patch guidance is available from sonicwall security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-20021.

Fix CVE-2021-20021 - CRITICAL sonicwall email security

Q: Which products are affected by CVE-2021-20021?

11 products: sonicwall email security, sonicwall email security appliance 9000 firmware, sonicwall email security appliance 3300 firmware, sonicwall email security appliance 4300 firmware, sonicwall email security appliance 8300 firmware, and 6 more.

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.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-269 · Improper Privilege Management CWE-269 · Improper Privilege Management

Metadata

Primary Vendor: SONICWALL
Published: 4/9/2021
Last Modified: 11/10/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

sonicwall : email_securitysonicwall : email_security_appliance_9000_firmwaresonicwall : email_security_appliance_3300_firmwaresonicwall : email_security_appliance_4300_firmwaresonicwall : email_security_appliance_8300_firmwaresonicwall : email_security_appliance_5000_firmwaresonicwall : email_security_appliance_7000_firmwaresonicwall : email_security_appliance_5050_firmwaresonicwall : email_security_appliance_7050_firmwaresonicwall : email_security_virtual_appliancesonicwall : hosted_email_security

Remediation Guidance

Executive Summary

View on NIST NVD