CVE-2021-20039Public exploitNetwork attack vector

Root command execution via newline filter bypass

Published Dec 8, 2021 · Updated Sep 5, 2025

OS command injection in SonicWall SMA 100 Series firmware allows remote authenticated users to execute arbitrary commands as root. The viewcert certificate-deletion handler passes the CERT directory value into an rm command after filters fail to reject newline separators, letting injected lines reach system. Only administrators can manipulate certificates, and appliances with licensed and enabled WAF are not affected; successful exploitation grants root control.

CVSS severity8.8
High
EPSS probability78.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in SonicWall SMA 100 Series firmware allows remote authenticated users to execute arbitrary commands as root. The viewcert certificate-deletion handler passes the CERT directory value into an rm command after filters fail to reject newline separators, letting injected lines reach system. Only administrators can manipulate certificates, and appliances with licensed and enabled WAF are not affected; successful exploitation grants root control.

The record

CVE
CVE-2021-20039
Published
Dec 8, 2021
Updated
Sep 5, 2025
Vendor
SonicWall
Product
Secure Mobile Access (SMA) 100 Series
Classifications
CWE-78, T1059.004, T1068
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.2.0.8-37sv and earlier
  2. Affected versionversion=10.2.1.1-19sv and earlier
  3. Affected versionversion=10.2.1.2-24sv and earlier
  4. Affected versionversion=9.0.0.11-31sv and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

SonicWall · Secure Mobile Access (SMA) 100 Seriesversion=10.2.0.8-37sv and earlier; version=10.2.1.1-19sv and earlier; version=10.2.1.2-24sv and earlier; version=9.0.0.11-31sv and earlier

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Unix Shell
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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