Home/CVE/Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allo
CVE

CVE-2021-20039

Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allo

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.

HIGH · CVSS 8.8 EPSS 0.82461
Act now
  • EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
  • EPSS percentile: top 1% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
▤

Affected Products & Versions

5
sonicwall sma 200 firmwareall versions
sonicwall sma 210 firmwareall versions
sonicwall sma 410 firmwareall versions
sonicwall sma 400 firmwareall versions
sonicwall sma 500v firmwareall versions
⚠

Public Exploits & PoCs

1
pocpacketstormsecurity.com · SonicWall-SMA-100-Series-Authenticated-Command-Injection....packetstormsecurity.com
◈

Detection Rules (IDS/IPS)

1
et-openET EXPLOIT SonicWall SMA Authenticated Command Injection Attempt CVE-2021-20039attempted-admin
Open rulesets (ET Open, Snort Community, abuse.ch) link to source. Commercial rulesets are reference-only.
▣

Scoring & Timeline

8.8
HIGH · CVSS v3.1 · PSIRT@sonicwall.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD08 Dec 2021 · 10:15 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026Vendor Advisory
https://attackerkb.com/topics/9szJhq46lw/cve-2021-20039/rapid7-analysis
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin