Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 17 Nov 2021. Known ransomware use
Email SecurityApplication · Sonicwall

CVE-2021-20022

HIGH · 7.2 CVSS v3.1 Published 2021-04-09
Fix available
A fix is available. Upgrade to 10.0.9.6103 / 10.0.9.6105 or later.
See remediation →
100/100
Remediation priority · Urgent
In the wild Ransomware Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to upload an arbitrary file to the remote host.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A post-authenticated arbitrary file upload vulnerability exists in SonicWall Email Security version 10.0.9.x. An authenticated attacker can exploit this to upload arbitrary files to the remote host, potentially achieving remote code execution by uploading malicious web shells or other payloads.

MitigationApply the vendor-provided patch or upgrade to a patched version of SonicWall Email Security. Additionally, restrict administrative access to trusted IP addresses and monitor for unauthorized file uploads.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Email SecurityApplication
Affected:< 10.0.9.6103
Email Security Appliance 9000 FirmwareOperating system
Affected:< 10.0.9.6105
Email Security Appliance 3300 FirmwareOperating system
Affected:< 10.0.9.6105
Email Security Appliance 4300 FirmwareOperating system
Affected:< 10.0.9.6105
Email Security Appliance 8300 FirmwareOperating system
Affected:< 10.0.9.6105
Email Security Appliance 5000 FirmwareOperating system
Affected:< 10.0.9.6105
Email Security Appliance 7000 FirmwareOperating system
Affected:< 10.0.9.6105
Email Security Appliance 5050 FirmwareOperating system
Affected:< 10.0.9.6105

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed SonicWall Email Security version
    Log into the admin console and navigate to System > About or Settings > License to view the exact software version number
    Affected if version is below 10.0.9.6103 for the software version
  2. Check appliance firmware version
    Access the appliance console or admin interface and locate the firmware version under System Information or Device Status
    Affected if firmware version is below 10.0.9.6105 for any of the listed appliance models (9000, 3300, 4300, 8300, 5000, 7000, 5050)
  3. Verify admin interface exposure
    Determine if the SonicWall admin web interface (typically ports 443 or 4433) is accessible from untrusted network segments or the internet
    Affected if the admin interface is exposed to networks outside the trusted internal environment
  4. Review admin account security
    Audit admin user accounts in the SonicWall console under Users > Admin Users or Account Settings to verify credential strength and access necessity
    Affected if weak passwords, default credentials, or unnecessary admin accounts exist on the system

The environment is affected if the installed SonicWall Email Security version is below 10.0.9.6103 (software) or the appliance firmware is below 10.0.9.6105, AND the admin interface is accessible to an attacker who could obtain valid credentials.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.9.6103 / 10.0.9.6105 or later
Fixed in 10.0.9.610310.0.9.6105
Interim mitigation

Apply the vendor-provided patch or upgrade to a patched version of SonicWall Email Security. Additionally, restrict administrative access to trusted IP addresses and monitor for unauthorized file uploads.

Recommended fix High confidence

SonicWall Email Security version 10.0.9.6103 or later (or Appliance Firmware 10.0.9.6105 or later)

  1. 1. Log into the SonicWall Email Security admin console and navigate to System > Status to confirm the current installed version
  2. 2. If version is below 10.0.9.6103 (Email Security) or 10.0.9.6105 (Appliance Firmware), initiate upgrade process
  3. 3. Back up the current configuration from System > Backup/Restore before proceeding with the upgrade
  4. 4. Download the appropriate fixed firmware version (10.0.9.6103 or later for Email Security; 10.0.9.6105 or later for Appliance models) from the official SonicWall support portal at support.sonicwall.com
  5. 5. Apply the firmware update via System > Firmware Update or the appropriate upgrade mechanism for your appliance model
  6. 6. After reboot, verify the new version is installed by checking System > Status
  7. 7. Validate that the unrestricted file upload vulnerability is remediated by confirming file upload restrictions are enforced as expected
Caveat Standard firmware upgrade risks apply - ensure configuration backup before upgrading; plan for brief downtime during the update process

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Email Security Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-20022 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-20022 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data