CVE-2021-20042: SonicWall SMA 200 Firmware

Critical severity, CVSS 9.8. EPSS: 3.7% chance of exploitation in the next 30 days.

An unauthenticated remote attacker can use SMA 100 as an unintended proxy or intermediary undetectable proxy to bypass firewall rules. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

Affected products

• SonicWall SMA 200 Firmware: version 9.0.0.11-31sv only; version 10.2.0.8-37sv only; version 10.2.1.1-19sv only
• SonicWall SMA 210 Firmware: version 9.0.0.11-31sv only; version 10.2.0.8-37sv only; version 10.2.1.1-19sv only
• SonicWall SMA 400 Firmware: version 9.0.0.11-31sv only; version 10.2.0.8-37sv only; version 10.2.1.1-19sv only
• SonicWall SMA 410 Firmware: version 9.0.0.11-31sv only; version 10.2.0.8-37sv only; version 10.2.1.1-19sv only
• SonicWall SMA 500v Firmware: version 9.0.0.11-31sv only; version 10.2.0.8-37sv only; version 10.2.1.1-19sv only

Published 2021-12-08. Last modified 2026-06-17.