How severe is CVE-2021-20019?

CVE-2021-20019 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-20019 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20019?

CVE-2021-20019 primarily affects Sonicwall Sonicos. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20019?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-20019 published?

CVE-2021-20019 was published on 2021-06-23 and last updated on 2026-06-17.

CVE-2021-20019

CVE-2021-20019 is a high-severity vulnerability in Sonicwall Sonicos with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Sonicwall Sonicos
Published: 2021-06-23
Last modified: 2026-06-17

Description

A vulnerability in SonicOS where the HTTP server response leaks partial memory by sending a crafted HTTP request, this can potentially lead to an internal sensitive data disclosure vulnerability.

Frequently asked questions

What is CVE-2021-20019?: A vulnerability in SonicOS where the HTTP server response leaks partial memory by sending a crafted HTTP request, this can potentially lead to an internal sensitive data disclosure vulnerability.
How severe is CVE-2021-20019?: CVE-2021-20019 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-20019 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20019?: CVE-2021-20019 primarily affects Sonicwall Sonicos. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20019?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-20019 published?: CVE-2021-20019 was published on 2021-06-23 and last updated on 2026-06-17.

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0006

Affected products (5)

cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sonicos:6.0.5.3-94o:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sonicos:6.5.1.12-3n:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sonicos:6.5.4.7-83n:*:*:*:*:*:*:*
cpe:2.3:o:sonicwall:sonicosv:6.5.4.4-44v-21-955:*:*:*:*:*:*:*

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