Cyber Resilience

CVE-2021-20028

SQLi in Sonicwall Sma 210 Firmware 8.0.0.0 – 9.0.0.10-28sv

CISA KEVActive ExploitationEUVD ExploitedRansomware-linkedSQLi
Published
04 August 2021
Modified
31 October 2025
KEV Added
28 March 2022
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.30 98th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2021-20028 is a critical-severity SQL Injection (CWE-89) vulnerability in Sonicwall Sma 210 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability is a SQL injection flaw (CWE-89) caused by improper neutralization of SQL commands. It affects end-of-life SonicWall Secure Remote Access (SRA) appliances running all 8.x firmware versions and 9.0.0.9-26sv or earlier. The issue carries a CVSS 3.1 base score of 9.8.

Remote unauthenticated attackers can exploit the flaw over the network without user interaction to read, modify, or delete database contents and potentially achieve full control of the affected appliance, resulting in complete loss of confidentiality, integrity, and availability.

The vulnerability is documented in SonicWall advisory SNWLID-2021-0017 and appears in CISA's catalog of known exploited vulnerabilities, confirming observed in-the-wild exploitation. Because the products have reached end-of-life status, no patches are expected; organizations should migrate away from the affected SRA appliances.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Improper neutralization of a SQL Command leading to SQL Injection vulnerability impacting end-of-life Secure Remote Access (SRA) products, specifically the SRA appliances running all 8.x firmware and 9.0.0.9-26sv or earlier

CWE(s)
KEV Date Added
28 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2021-20016Same product: Sonicwall Sma 210both on KEV
CVE-2019-7481Same vendor: Sonicwallboth on KEV
CVE-2023-34133Same vendor: Sonicwall
CVE-2016-2386Shared CWE-89both on KEV
CVE-2024-6670Shared CWE-89both on KEV
CVE-2024-29824Shared CWE-89both on KEV
CVE-2020-12271Shared CWE-89both on KEV
CVE-2020-29574Shared CWE-89both on KEV
CVE-2021-44026Shared CWE-89both on KEV
CVE-2024-9379Shared CWE-89both on KEV

Affected Assets

sonicwall
sma 210 firmware
8.0.0.0 — 9.0.0.10-28sv
sonicwall
sma 410 firmware
8.0.0.0 — 9.0.0.10-28sv
sonicwall
sma 500v firmware
8.0.0.0 — 9.0.0.10-28sv
sonicwall
sra 4600 firmware
8.0.0.0 — 9.0.0.10-28sv
sonicwall
sra 1600 firmware
8.0.0.0 — 9.0.0.10-28sv
sonicwall
sra va firmware
8.0.0.0 — 9.0.0.10-28sv

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V6.2.5

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.

addresses: CWE-89

Penetration testing uses SQL injection payloads against database interfaces, identifying and supporting fixes for SQL injection weaknesses.

addresses: CWE-89

Validates query inputs to prevent SQL syntax or command manipulation.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target injection flaws during coding and review so largely prevent CWE-89 introduction, yet the single broad outcome leaves residual risk from incomplete neutralization techniques or missed edge cases.

PR.AT-02 partial match
prevents

Training raises developer awareness of SQLi risks and can reduce introduction likelihood (partial) but removes none of the actual coding flaw's risk by itself since technical neutralization is still required.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

The same secure-coding and static-analysis activities surface missing neutralization of SQL metacharacters before the system is accepted.

prevents

Early warnings and shared best-practice information help organizations apply the latest remediation techniques against SQL-injection vulnerabilities.

prevents

Threat-intelligence feeds that surface new SQL-injection campaigns enable rapid updates to query-construction defenses and detection signatures before exploitation occurs.

prevents

Secure-coding rules and security testing phases mandate the use of parameterized queries or equivalent escaping, preventing the construction of dynamic SQL statements from untrusted input.

prevents

Language-specific secure coding rules, peer review and SAST together prevent the construction of SQL statements from untrusted data without proper parameterization or escaping.

References