Exploited· due 2021-11-174.9mediumMediumused in ransomware
CVE-2021-20023
Sonicwall Email Security
SonicWall Email Security version 10.0.9.x contains a vulnerability that allows a post-authenticated attacker to read an arbitrary file on 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, an administrative account is needed.
- Beyond that, no action by a user is required.
Scoring
- CVSS
- 4.9 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N- Weakness
- CWE-22
- Assigned by
- PSIRT@sonicwall.com
Dates
- Published
- 2021-04-20
- 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- 10.0.9.6173
- Microsoft Windowsall versions
- Sonicwall Email Security Appliance 9000 Firmware- 10.0.9.6177
- Sonicwall Email Security Appliance 9000all versions
- Sonicwall Email Security Appliance 3300 Firmware- 10.0.9.6177
- Sonicwall Email Security Appliance 3300all versions
- Sonicwall Email Security Appliance 4300 Firmware- 10.0.9.6177
- Sonicwall Email Security Appliance 4300all versions
- Sonicwall Email Security Appliance 8300 Firmware- 10.0.9.6177
- Sonicwall Email Security Appliance 8300all versions
- Sonicwall Email Security Appliance 5000 Firmware- 10.0.9.6177
- Sonicwall Email Security Appliance 5000all versions
As listed in the NVD configuration data. Not a statement about your estate.