CVE-2021-20041: SonicWall SMA 200 Firmware

High severity, CVSS 7.5. EPSS: 21.2% chance of exploitation in the next 30 days.

An unauthenticated and remote adversary can consume all of the device's CPU due to crafted HTTP requests sent to SMA100 /fileshare/sonicfiles/sonicfiles resulting in a loop with unreachable exit condition. 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.