Exploited· due 2021-11-179.8criticalCriticalused in ransomware
CVE-2021-20021
Sonicwall Email Security
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.
Exploitation status
- CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
- It is known to have been used in ransomware campaigns.
- US federal civilian agencies are required to remediate it by 2021-11-17. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.
- A vendor advisory or patch reference has been published.
Required action
Apply updates per vendor instructions.
CISA’s wording, unedited.
What the metrics mean
- It is reachable over a network, without needing local access.
- For an attacker who can reach it, no special conditions are needed to exploit it.
- To exploit it, no account is needed.
- Beyond that, no action by a user is required.
Scoring
- CVSS
- 9.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness
- CWE-269
- Assigned by
- PSIRT@sonicwall.com
Dates
- Published
- 2021-04-09
- Last modified
- 2026-08-12
- Added to KEV
- 2021-11-03
- Remediation due
- 2021-11-17
- Sources
- CISA KEV, NVD
Affected products
- Sonicwall Email Security- 10.0.9.6103
- Microsoft Windowsall versions
- Sonicwall Email Security Appliance 9000 Firmware- 10.0.9.6105
- Sonicwall Email Security Appliance 9000all versions
- Sonicwall Email Security Appliance 3300 Firmware- 10.0.9.6105
- Sonicwall Email Security Appliance 3300all versions
- Sonicwall Email Security Appliance 4300 Firmware- 10.0.9.6105
- Sonicwall Email Security Appliance 4300all versions
- Sonicwall Email Security Appliance 8300 Firmware- 10.0.9.6105
- Sonicwall Email Security Appliance 8300all versions
- Sonicwall Email Security Appliance 5000 Firmware- 10.0.9.6105
- Sonicwall Email Security Appliance 5000all versions
As listed in the NVD configuration data. Not a statement about your estate.