How severe is CVE-2021-20035?

CVE-2021-20035 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-20035 being actively exploited?

Yes. CVE-2021-20035 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2025-04-16, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-20035?

CVE-2021-20035 primarily affects Sonicwall Sma 200 Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20035?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-20035 have an EU (EUVD) identifier?

Yes. CVE-2021-20035 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-7498. It is also flagged as exploited in the EUVD (since 2025-04-16).

When was CVE-2021-20035 published?

CVE-2021-20035 was published on 2021-09-27 and last updated on 2026-06-17.

CVE-2021-20035

CVE-2021-20035 is a medium-severity vulnerability in Sonicwall Sma 200 Firmware with a CVSS 3.x base score of 6.5. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2025-04-16). The underlying weakness is classified as CWE-78.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 6.8
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2025-04-16)
EU (EUVD) id: EUVD-2021-7498
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2025-04-16)
Weakness: CWE-78
Affected product: Sonicwall Sma 200 Firmware
Published: 2021-09-27
Last modified: 2026-06-17

Description

Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.

Frequently asked questions

What is CVE-2021-20035?: Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.
How severe is CVE-2021-20035?: CVE-2021-20035 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-20035 being actively exploited?: Yes. CVE-2021-20035 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2025-04-16, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-20035?: CVE-2021-20035 primarily affects Sonicwall Sma 200 Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20035?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-20035 have an EU (EUVD) identifier?: Yes. CVE-2021-20035 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-7498. It is also flagged as exploited in the EUVD (since 2025-04-16).
When was CVE-2021-20035 published?: CVE-2021-20035 was published on 2021-09-27 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:sonicwall:sma_200_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sma_210_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sma_400_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sma_410_firmware:*:*:*:*:*:*:*:*
cpe:2.3:a:sonicwall:sma_500v:*:*:*:*:*:*:*:*

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