Cyber Resilience

CVE-2021-20039

HighPublic PoCRCE

Published: 08 December 2021

Published
08 December 2021
Modified
05 September 2025
KEV Added
—
Patch
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CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.8246 99.3th percentile
Risk Priority 67 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20039 is a high-severity OS Command Injection (CWE-78) vulnerability in Sonicwall Sma 200 Firmware. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 0.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

CWE(s)
CWE-78

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

sonicwall
sma 200 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 210 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 410 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 400 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 500v firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

References