IRONSMITHINTEL
MEDIUMCVSS6.5
|
Actively Exploited
|CISA KEV|CVE-2021-20035|Auth: low — authenticated user|Reboot: required|Manual only

SonicWall SMA100 Appliances OS Command Injection Vulnerability (CVE-2021-20035)

SonicWall SMA100 appliances contain an OS command injection vulnerability in the management interface that allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user, which could potentially lead to code execution.

Published Sep 27, 2021 · Updated May 17, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, with a low-privilege account, can achieve partial data exposure, complete denial of service or system unavailability. Federal agencies are required to remediate by 2025-05-07 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a OS Command Injection (CWE-78) vulnerability in SonicWall SMA100 Appliances. Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS. Exploitation requires remote network access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running sma 200 firmware: v < 9.0.0.11-31sv, 10.2.0.0 ≤ v < 10.2.0.8-37sv, 10.2.1.0 ≤ v < 10.2.1.1-19sv; sma 210 firmware: v < 9.0.0.11-31sv, 10.2.0.0 ≤ v < 10.2.0.8-37sv, 10.2.1.0 ≤ v < 10.2.1.1-19sv; sma 400 firmware: v < 9.0.0.11-31sv, 10.2.0.0 ≤ v < 10.2.0.8-37sv, 10.2.1.0 ≤ v < 10.2.1.1-19sv; sma 410 firmware: v < 9.0.0.11-31sv, 10.2.0.0 ≤ v < 10.2.0.8-37sv, 10.2.1.0 ≤ v < 10.2.1.1-19sv; sma 500v: v < 9.0.0.11-31sv, 10.2.0.0 ≤ v < 10.2.0.8-37sv, 10.2.1.0 ≤ v < 10.2.1.1-19sv
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2025-04-16 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2025-05-07.

How to patch

Manual remediation steps

1
Identify affected hosts: query inventory for network-security installs in scope.
2
Apply the vendor security update referenced in CVE-2021-20035's advisory. No specific KB/version is encoded yet — consult the linked MSRC/vendor URL.
3
Verify the fix per the vendor's published verification steps.
4
Document the remediation in your change ticket and re-scan with your vulnerability scanner to confirm closure.
PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2021-20035↗ MSRC Advisory↗ NVD↗ Vendor Advisory