What it is
CVE-2021-20016 is an unauthenticated vulnerability affecting SonicWall SonicWall SMA100. A SQL-Injection vulnerability in the SonicWall SSLVPN SMA100 product allows a remote unauthenticated attacker to perform SQL...
Vulnerability report
Active exploitation observed
Confirmed confidence
In CISA KEV
CVE-2021-20016
SonicWall SMA100
SonicWall / SonicWall SMA100 · SMA100 build version 10.x
- Severity
- CVSS 9.8 · Critical
- Confidence
- Confirmed
- Exploit status
- Observed in sensors
- EPSS
- 40.0%
- First observed
- 27 Jun 2026
- Last observed
- 20 Aug 2026
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. Previdian sensors observed exploitation attempts with confirmed confidence.
Who is affected?
SonicWall / SonicWall SMA100 sma100 build version 10.x.
What should we do?
Patch immediately, validate internet-facing exposure, and monitor for matching requests.
Overview
SonicWall SMA100
A SQL-Injection vulnerability in the SonicWall SSLVPN SMA100 product allows a remote unauthenticated attacker to perform SQL query to access username password and other session related information.
This vulnerability impacts SMA100 build version 10.x.
Vendor
Product
Affected
Status
SonicWall
SonicWall SMA100
SMA100 build version 10.x
Affected
- Published
- 03 Feb 2021
- Exploitation Reported
- 03 Nov 2021
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
cisa
malware
ransomware
edge
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-20016
- psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0001 psirt.global.sonicwall.com · CVE Record https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0001
Exploitation evidence
Why Previdian marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the Previdian record.
Active exploitation observed
Previdian sensor
First-party sensor telemetry confirms matching exploitation attempts.
Used in malware
CISA
Malware families have been linked to exploitation of this CVE.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-03 00:00 UTC |
| Tenable Blog | 2026-07-15 17:14 UTC |
| Previdian | 2026-07-23 11:02 UTC |
| CVE | 2026-08-12 04:21 UTC |
Operational indicators for this CVE are listed under Detection.
Sensor telemetry
First-party evidence of exploitation activity
Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.
2
Attempts observed
2
Unique attacker IPs
2
Attacker countries
GB · US
2
Sensors observed
Exploitation attempts over the last 61 days
Daily events observed by Previdian sensors
Updated 25 Aug 2026
26 Jun
9 Jul
22 Jul
4 Aug
25 Aug
First observed 27 Jun 2026 · Last observed 20 Aug 2026
Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 1
- User-Agents
- 1
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Attacker IP Indicators
Attacker IP indicators observed · available in Pro and Enterprise.
Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.
Learn about Pro API accessRisk and context
Severity, weaknesses, and research context
CVSS v3.1
9.8
Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
40.0%
Weaknesses
Recent mention · Tenable Blog
CVE-2026-15409, CVE-2026-15410: SonicWall SMA 1000 zero-day vulnerabilities exploited in the wild
SonicWall patched two recently exploited zero-day vulnerabilities in its SMA 1000 Series secure remote access appliances which may have been chained for unauthenticated remote code execution.Key takeawaysCVE-2026-15409 and CVE-2026-15410 are a pair of exploited vulnerabilities...
Read full advisoryAll CVSS Scores
CVSS v3.1
9.8
Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
7.5
High
AV:N/AC:L/Au:N/C:P/I:P/A:P
Timeline
From disclosure to observed exploitation
-
KEV confirmed by CVE
Exploitation attested by an external source
-
KEV confirmed by Tenable Blog
Exploitation attested by an external source
-
Observed by Previdian sensors
Evidence-backed exploitation signal
-
Indicators of compromise added (24)
Indicators of compromise recorded
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
First public exploitation report
Exploit observed in malware
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2021-20016
Free JSON includes basic KEV fields{
"cve_id": "CVE-2021-20016",
"confidence": "Confirmed",
"cvss_score": 9.8,
"cvss_estimated": false,
"epss_score": 0.40038,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "attempts": 2, "sensors": 2 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.