CVE-2021-20021
CRITICALCISA KEVEPSS 100th pctlDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 100% of all known CVEs.
SonicWall Email Security Improper Privilege Management Vulnerability
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.
Apply updates per vendor instructions.
Remediation due: 2021-11-17
Associated with ransomware campaigns
References
Related Vulnerabilities
Other CWE-269 (Improper Privilege Management) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2017-12635 | Critical | 9.8 | 100% | - | Fix |
| CVE-2022-24637 | Critical | 9.8 | 99% | - | Fix |
| CVE-2017-5689 | Critical | 9.8 | 92% | KEV | Fix |
| CVE-2020-3243 | Critical | 9.8 | 88% | - | - |
| CVE-2024-21888 | High | 8.8 | 87% | - | - |
| CVE-2022-0441 | Critical | 9.8 | 85% | - | Fix |
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-10.