CVE-2021-20021
9.8 · CRITICAL Actively ExploitedOverview
CVE-2021-20021 is a critical-severity vulnerability affecting sonicwall email_security. It was published on April 9, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL). This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
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.
Remediation
Check the references section for vendor advisories and patches from sonicwall. Update email_security to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| sonicwall | email_security | >= 0, < 10.0.9.6103 | Affected |
| sonicwall | email_security_appliance_9000_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_3300_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_4300_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_8300_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_5000_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_7000_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_5050_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_appliance_7050_firmware | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | email_security_virtual_appliance | >= 0, < 10.0.9.6105 | Affected |
| sonicwall | hosted_email_security | >= 0, < 10.0.9.6103 | Affected |
Frequently Asked Questions
What is CVE-2021-20021?
CVE-2021-20021 is a critical-severity vulnerability affecting sonicwall email_security. It was published on April 9, 2021 and has a CVSS 3.1 base score of 9.8 (CRITICAL). This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.
How severe is CVE-2021-20021?
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-20021?
Check the references section for vendor advisories and patches from sonicwall. Update email_security to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-20021?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-20021 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
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