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Weekly Signal
Live intelligence Updated 22 Aug 2026 · 21:24 UTC

SonicWall · Sma 200 Firmware, Sma 210 Firmware, Sma 400 Firmware +3 more

CVE-2021-20035

SonicWall SMA100 Appliances OS Command Injection Vulnerability

Recommended action

Validate affected assets and exposure now, then remediate on an accelerated schedule. SonicWall Security advisory SNWLID 2021 0022

View response plan
CVSS6.5
EPSS4.1%
KEVYes
ExploitationConfirmed exploitation
RemediationNot yet verified ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 4.1%; technical severity is CVSS 6.5.

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.

Who should care

  • Teams operating Sma 200 Firmware, Sma 210 Firmware, Sma 400 Firmware +3 more
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Sma 200 Firmware, Sma 210 Firmware, Sma 400 Firmware +3 more is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. SonicWall Security advisory SNWLID 2021 0022
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Treatment intelligence

Remediation intelligence

Not yet verified

Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.

Verification noteAutomated link verification has not completed for this guidance yet.

Advisory

Required Action

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE
CWE-78
Affected versions
SonicWall Sma 200 Firmware (End Excluding 9.0.0.11-31sv | Start Including 10.2.0.0, End Excluding 10.2.0.8-37sv | Start Including 10.2.1.0, End Excluding 10.2.1.1-19sv); SonicWall Sma 210 Firmware (End Excluding 9.0.0.11-31sv | Start Including 10.2.0.0, End Excluding 10.2.0.8-37sv | Start Including 10.2.1.0, End Excluding 10.2.1.1-19sv); SonicWall Sma 400 Firmware (End Excluding 9.0.0.11-31sv | Start Including 10.2.0.0, End Excluding 10.2.0.8-37sv | Start Including 10.2.1.0, End Excluding 10.2.1.1-19sv); SonicWall Sma 410 Firmware (End Excluding 9.0.0.11-31sv | Start Including 10.2.0.0, End Excluding 10.2.0.8-37sv | Start Including 10.2.1.0, End Excluding 10.2.1.1-19sv); SonicWall Sma 500v (End Excluding 9.0.0.11-31sv | Start Including 10.2.0.0, End Excluding 10.2.0.8-37sv | Start Including 10.2.1.0, End Excluding 10.2.1.1-19sv); SonicWall SMA100 Appliances
Fixed versions
SonicWall Sma 200 Firmware (Fixed from 9.0.0.11-31sv, 10.2.0.8-37sv, 10.2.1.1-19sv); SonicWall Sma 210 Firmware (Fixed from 9.0.0.11-31sv, 10.2.0.8-37sv, 10.2.1.1-19sv); SonicWall Sma 400 Firmware (Fixed from 9.0.0.11-31sv, 10.2.0.8-37sv, 10.2.1.1-19sv); SonicWall Sma 410 Firmware (Fixed from 9.0.0.11-31sv, 10.2.0.8-37sv, 10.2.1.1-19sv); SonicWall Sma 500v (Fixed from 9.0.0.11-31sv, 10.2.0.8-37sv, 10.2.1.1-19sv)
Published
27 September 2021
Attack vector
Network
Privileges required
Low
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 4.1%
  4. Signal calculated at 66

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.