NVD / CVE Program· CNA sonicwall

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…

CriticalCVSS 9.8 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: Now (action score 96/100)

CISA has confirmed exploitation in the wild (Nov 3, 2021); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Nov 17, 2021.
A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Probability of exploitation in the next 30 days: 88.7% (FIRST EPSS); higher than 99.7% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

Pre-auth

Published: Apr 9, 2021
Updated: Aug 12, 2026
EPSS: 88.7% · 99th percentile
CWE: CWE-269

Report tools

JSON

Action score

Now

Patch today or shut off access.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 30 / 30 · Listed
EPSS: 27 / 30 · 88.7%

CISA SSVC decision

Exploitation: active
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Nov 3, 2021. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Nov 17, 2021.

Known to be used in ransomware campaigns.

Get told when this record changes

In CISA KEV: exploitation in the wild confirmed
Weaponized exploit exists
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
sonicwall	email security	cpe:2.3:a:sonicwall:email_security
sonicwall	email security appliance 9000 firmware	cpe:2.3:o:sonicwall:email_security_appliance_9000_firmware
sonicwall	email security appliance 9000	cpe:2.3:h:sonicwall:email_security_appliance_9000
sonicwall	email security appliance 3300 firmware	cpe:2.3:o:sonicwall:email_security_appliance_3300_firmware
sonicwall	email security appliance 3300	cpe:2.3:h:sonicwall:email_security_appliance_3300
sonicwall	email security appliance 4300 firmware	cpe:2.3:o:sonicwall:email_security_appliance_4300_firmware
sonicwall	email security appliance 4300	cpe:2.3:h:sonicwall:email_security_appliance_4300
sonicwall	email security appliance 8300 firmware	cpe:2.3:o:sonicwall:email_security_appliance_8300_firmware
sonicwall	email security appliance 8300	cpe:2.3:h:sonicwall:email_security_appliance_8300
sonicwall	email security appliance 5000 firmware	cpe:2.3:o:sonicwall:email_security_appliance_5000_firmware
sonicwall	email security appliance 5000	cpe:2.3:h:sonicwall:email_security_appliance_5000
sonicwall	email security appliance 7000 firmware	cpe:2.3:o:sonicwall:email_security_appliance_7000_firmware

and 8 more

Versions reported by the vendor

Affected version ranges reported by the assigning authority (sonicwall). Independent of NVD's CPE analysis and usually ahead of it.

SonicWall Email Security
- 10.0.9 and earlieraffected

Affected versions · NVD (11)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

sonicwall email securitybefore 10.0.9.6103
sonicwall email security appliance 3300 firmwarebefore 10.0.9.6105
sonicwall email security appliance 4300 firmwarebefore 10.0.9.6105
sonicwall email security appliance 5000 firmwarebefore 10.0.9.6105
sonicwall email security appliance 5050 firmwarebefore 10.0.9.6105
sonicwall email security appliance 7000 firmwarebefore 10.0.9.6105
sonicwall email security appliance 7050 firmwarebefore 10.0.9.6105
sonicwall email security appliance 8300 firmwarebefore 10.0.9.6105
sonicwall email security appliance 9000 firmwarebefore 10.0.9.6105
sonicwall email security virtual appliancebefore 10.0.9.6105
sonicwall hosted email securitybefore 10.0.9.6103

Same product

sonicwall: all records

Other highest-scoring records for the same primary product.

CVE-2021-20023SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to read an arbitrary file on…KEV
65This week
CVE-2021-20022SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to upload an arbitrary file to…KEV
63This week
CVE-2026-66150Improper Control of Generation of Code ('Code Injection') Vulnerability in the SonicWall Email Security appliance allows an authenticated…
31Monitor

Published before and after this one in the same product

Later →CVE-2023-0655Feb 13, 2023 · SonicWall Email Security contains a vulnerability that could permit a remote unauthenticated attacker access to an error page that includes…
21Monitor
Later →CVE-2024-22398Mar 14, 2024 · An improper Limitation of a Pathname to a Restricted Directory (Path Traversal) vulnerability in SonicWall Email Security Appliance could…
19Monitor
Later →CVE-2026-3468Mar 31, 2026 · A stored Cross-Site Scripting (XSS) vulnerability has been identified in the SonicWall Email Security appliance due to improper…
19Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

Nuclei detection template ×1
Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Nuclei detection template	Nuclei template CVE-2021-20021	—
Proof-of-concept repository on GitHub	stars:2	2023-09-07

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedApr 9, 2021
CISA KEVNov 3, 2021+207 d
First PoCSep 7, 2023+880 d
TodayNov 14, 2026+2045 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0337 · Apr 21, 2021(SonicWall Güvenlik Zafiyeti)

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-269 · Improper Privilege Management

CVSS vector

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

nvd-primary

Root cause

To simplify setup, a service account is granted broad, cluster-wide permissions. The principle of least privilege is skipped during installation.

The bug in code

The whole CWE-269 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

yaml

1kind: ClusterRole
2rules:
3  - apiGroups: ["*"]
4    resources: ["*"]
5    verbs: ["*"]

Fixed

yaml

1kind: Role
2metadata:
3  namespace: lodos-system
4rules:
5  - apiGroups: ["apps"]
6    resources: ["deployments"]
7    verbs: ["get", "list", "update"]

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Abuse Elevation Control MechanismT1548

Change log (0)

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

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

Show all references (1 more)

www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20021

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records