CVE-2021-20035

MEDIUM

6.5

CVSS Score

Published: September 27, 2021 at 05:20 PM UTC

Updated: June 17, 2026 at 03:33 AM UTC

10 products affected across 1 vendorSMA 210 FirmwareSMA 410 FirmwareSMA 400 Firmware

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Severity

MEDIUM6.5

Exploitation

CISA KEV

Exploit prediction

EPSS 4%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score4.4%

EPSS (Exploit Prediction Scoring System) estimates a 4.4% chance this CVE is exploited in the wild within the next 30 days — higher than 91% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

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.

Required Action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Ransomware Use

Unknown

Added to KEV

Apr 16, 2025

Remediation Due

May 7, 2025

541 days overdue

Notes

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022

https://nvd.nist.gov/vuln/detail/CVE-2021-20035

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

SMA 200 Firmware · SonicWall

95%

v < 9.0.0.11-31sv10.2.0.0 ≤ v < 10.2.0.8-37sv10.2.1.0 ≤ v < 10.2.1.1-19sv

Affected range stops below 10.2.0.8-37sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 10.2.1.1-19sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.0.0.11-31sv, so it looks safe — our inference, not a vendor statement

sonicwall-sma-200 (same device)

SMA 210 Firmware · SonicWall

95%

v < 9.0.0.11-31sv10.2.0.0 ≤ v < 10.2.0.8-37sv10.2.1.0 ≤ v < 10.2.1.1-19sv

Affected range stops below 10.2.0.8-37sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 10.2.1.1-19sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.0.0.11-31sv, so it looks safe — our inference, not a vendor statement

sonicwall-sma-210 (same device)

SMA 400 Firmware · SonicWall

95%

v < 9.0.0.11-31sv10.2.0.0 ≤ v < 10.2.0.8-37sv10.2.1.0 ≤ v < 10.2.1.1-19sv

Affected range stops below 10.2.0.8-37sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 10.2.1.1-19sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.0.0.11-31sv, so it looks safe — our inference, not a vendor statement

sonicwall-sma-400 (same device)

SMA 410 Firmware · SonicWall

95%

v < 9.0.0.11-31sv10.2.0.0 ≤ v < 10.2.0.8-37sv10.2.1.0 ≤ v < 10.2.1.1-19sv

Affected range stops below 10.2.0.8-37sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 10.2.1.1-19sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.0.0.11-31sv, so it looks safe — our inference, not a vendor statement

sonicwall-sma-410 (same device)

SMA 500V · SonicWall

95%

v < 9.0.0.11-31sv10.2.0.0 ≤ v < 10.2.0.8-37sv10.2.1.0 ≤ v < 10.2.1.1-19sv

Affected range stops below 10.2.0.8-37sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 10.2.1.1-19sv, so it looks safe — our inference, not a vendor statement

Affected range stops below 9.0.0.11-31sv, so it looks safe — our inference, not a vendor statement

SMA100 Firmware · SonicWall

60%

v ≤ 10.2.0.7-34svv ≤ 10.2.1.0-17svv ≤ 9.0.0.10-28sv

Sma 200 · SonicWalldevice

80%

All versions

Sma 210 · SonicWalldevice

80%

All versions

Sma 400 · SonicWalldevice

80%

All versions

Sma 410 · SonicWalldevice

80%

All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022

References (2)

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022

US Government Resource

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20035

SSVC — Action Prioritization

SSVCActiveNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMCISA-ADP

Attack Vector: NETWORK
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusANALYZED

CWE

CWE-78

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