CVE-2021-20021A 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.
Updated under an hour ago ()
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It affects SonicWall Email Security and 10 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021, and it is known to be used in ransomware. Treat that date as your deadline.
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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.
- CVSS
- 9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-269
- Known exploited
- Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021; known ransomware useApply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 88.78% (percentile 100)
- Assigned by
- sonicwall
- NVD analysis
- Analyzed
- Record last updated
- Aug 12, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
SonicWall Email Security sonicwall:email_security (from the name) | 10.0.9 and earlier | CNA record |
sonicwall email_security sonicwall:email_security | before 10.0.9.6103 | NVD |
sonicwall email_security_appliance_9000_firmware sonicwall:email_security_appliance_9000_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_3300_firmware sonicwall:email_security_appliance_3300_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_4300_firmware sonicwall:email_security_appliance_4300_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_8300_firmware sonicwall:email_security_appliance_8300_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_5000_firmware sonicwall:email_security_appliance_5000_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_7000_firmware sonicwall:email_security_appliance_7000_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_5050_firmware sonicwall:email_security_appliance_5050_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_appliance_7050_firmware sonicwall:email_security_appliance_7050_firmware | before 10.0.9.6105 | NVD |
sonicwall email_security_virtual_appliance sonicwall:email_security_virtual_appliance | before 10.0.9.6105 | NVD |
sonicwall hosted_email_security sonicwall:hosted_email_security | before 10.0.9.6103 | NVD |
References
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0007x-refsource-confirm, vendor-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20021us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.