KEV Monitor
← Back to catalog

SonicWall · SonicWall Email Security

CVE-2021-20021

SonicWall Email Security Improper Privilege Management Vulnerability

CISA KEV record

CISA date added
2021-11-03
CISA due date
2021-11-17
Known ransomware use
Known

NVD risk context

9.8 CRITICAL

CVSS is a technical severity score. CISA’s KEV status remains the evidence that this vulnerability is known to be exploited.

View NVD record ↗
Attack vector
Network
The vulnerable service can be reached remotely over a network.
Attack complexity
Low
Exploitation does not require unusual conditions beyond normal attacker control.
Privileges required
None
The attacker does not need an existing account or privileges.
User interaction
None
No action by another user is required.

Description

SonicWall Email Security contains an improper privilege management vulnerability that allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20022 and CVE-2021-20023 to achieve privilege escalation.

Required action

Apply updates per vendor instructions.

NVD reference index

Vendor and remediation references

NVD has tagged these sources as vendor advisories, patches, mitigations, or release notes.

Other NVD references (1)

MITRE CWE context

CWE classification

CWE-306 Missing Authentication for Critical Function

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

View official MITRE CWE details ↗

NVD record timing

NVD record timeline

These dates describe NVD’s record, not CISA’s KEV addition or remediation due date.

NVD published
Apr 09, 2021, 06:15 PM UTC
When NVD first published this CVE record.
NVD last updated
Jun 17, 2026, 03:33 AM UTC
When NVD last changed its analysis or record data.
Advanced: view the technical CVSS vector

This standardized code is intended for security tools and technical analysts. The plain-language risk summary above explains its main points.

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

View NVD record ↗

CISA notes

https://nvd.nist.gov/vuln/detail/CVE-2021-20021