CVE-2021-20021

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.

Affected

SonicWall · Email Security

CVSS v3.1 NVD

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

CVSS v2.0 NVD

7.5 HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS

88.78% chance of exploitation in the next 30 days, 100th percentile

CISA KEV

added 2021-11-03, used in ransomware campaigns

Nuclei

critical · CWE-269

Published

2021-04-09

Updated

2026-08-12

Proof-of-concept exploits (1)

• SUPRAAA-1337/CVE-2021-200212★ · 2023-09-08

Nuclei templates (1)

• projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-20021.yaml

Security advisories

• https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0007

References

• CVE Record
• NVD entry

Related

• CVE-2021-34523
• CVE-2022-41082
• CVE-2025-3102
• CVE-2025-31161