IRONSMITHINTEL
HIGHCVSS7.2
|
Actively Exploited
|CISA KEV|CVE-2021-20022|Auth: high — administrative privileges|Reboot: required|Manual only

SonicWall SonicWall Email Security < 10.0.9

SonicWall Email Security contains an unrestricted upload of file with dangerous type vulnerability that allows a post-authenticated attacker to upload a file to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20021 and CVE-2021-20023 to achieve privilege escalation.

Published Apr 9, 2021 · Updated May 17, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, with administrative privileges, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2021-11-17 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Unrestricted File Upload (CWE-434) vulnerability in SonicWall SonicWall Email Security. 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. Exploitation requires remote network access, low attack complexity, an administrative account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running email security: v < 10.0.9.6103; email security appliance 9000 firmware: v < 10.0.9.6105; email security appliance 3300 firmware: v < 10.0.9.6105; email security appliance 4300 firmware: v < 10.0.9.6105; email security appliance 8300 firmware: v < 10.0.9.6105; email security appliance 5000 firmware: v < 10.0.9.6105; email security appliance 7000 firmware: v < 10.0.9.6105; email security appliance 5050 firmware: v < 10.0.9.6105; email security appliance 7050 firmware: v < 10.0.9.6105; email security virtual appliance: v < 10.0.9.6105; hosted email security: v < 10.0.9.6103
Fixed in10.0.9
Real-world incidentsWhat we've seen

CISA confirms this CVE has been used in known ransomware campaigns. Added to the KEV catalog on 2021-11-03; federal agencies required to remediate by 2021-11-17.

How to patch

Manual remediation steps

1
Identify affected hosts: query inventory for network-security installs in scope.
2
Upgrade to version 10.0.9 or later. Stage in a test ring before broad deployment.
3
Verify by checking the installed version on a sample of remediated hosts.
4
Document the remediation in your change ticket and re-scan with your vulnerability scanner to confirm closure.
PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2021-20022↗ MSRC Advisory↗ NVD↗ Vendor Advisory