Security readout for executives and security teams
Plain-English summary
A remote attacker can target an affected SonicWall SMA100 without credentials and manipulate its database queries. This could expose usernames, passwords, and session information used for remote access. Because the flaw is critical and appears in CISA’s Known Exploited Vulnerabilities catalog, affected appliances require immediate attention.
Executive priority
Immediate. Determine whether the organization operates affected SMA100 appliances, remediate them using current SonicWall guidance, and assess exposed systems for possible compromise. The combination of unauthenticated remote access, potential credential disclosure, critical severity, and known exploitation creates material risk to remote-access security.
Technical view
CVE-2021-20016 is a remotely reachable SQL-injection vulnerability (CWE-89) affecting SMA100 build version 10.x. It requires no privileges or user interaction and has low attack complexity. Its CVSS 3.1 score is 9.8, with high confidentiality, integrity, and availability impacts, although the supplied description specifically confirms access to credentials and session-related information.
Likely exposure
Organizations using network-accessible SonicWall SMA100 appliances running 10.x builds are potentially exposed. Internet-facing remote-access deployments warrant the greatest urgency. The supplied sources do not identify exact affected models, fixed releases, deployment prevalence, or exposed-instance counts.
Exploitation context
CISA lists CVE-2021-20016 in its Known Exploited Vulnerabilities catalog, supporting known exploitation in the wild. The supplied evidence does not establish current campaign frequency, targeted organizations, exploitation methods, or specific indicators of compromise.
Researcher notes
The confirmed weakness is SQL injection in SMA100 10.x, reachable remotely without authentication. Public evidence supplied here does not identify the vulnerable endpoint, query construction, affected model subset, fixed release, or exploitation artifacts. Avoid assuming that every suspicious authentication event proves exploitation; correlate appliance, identity, and session evidence.
Mitigation direction
- Identify all SMA100 appliances running 10.x builds and prioritize them for immediate vendor-directed remediation.
- Review SNWLID-2021-0001 and apply SonicWall's currently recommended fix or mitigation for the exact build.
- Use only vendor-approved compensating controls if remediation cannot be completed immediately.
- Escalate any internet-exposed affected appliance for urgent incident-response review.
Validation and detection
- Confirm each SMA100 appliance and installed build; treat 10.x builds as affected unless SonicWall guidance states otherwise.
- Verify applied remediation against SonicWall advisory SNWLID-2021-0001 and retain evidence.
- Review appliance, authentication, and session logs for unexplained access; the supplied sources provide no specific indicators.
- Confirm affected appliances are no longer running a vulnerable build after remediation.
Public sources used
The source record changed after analysis: Material source record changed after analysis.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-89: Database access and collection lookup
Injection into data stores can inform collection, data access, and exfiltration detection reviews. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-20016 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- Added to KEVCISA-ADP
CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.
- ADP timelineCISA-ADP
CVE-2021-20016 added to CISA KEV
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2021-11-03T00:00:00.000Z: CVE-2021-20016 added to CISA KEV
Source materials
- CVE List V5 sourceCVE List V5
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0001CVE reference, sonicwall · x_refsource_CONFIRM
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20016CVE reference, CISA-ADP · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.