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.

Published: 2021-06-23 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20019 is rated Moderate Risk (54.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.41%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-20019

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.04% 1.41% +0.37%
2 2025-12-28 0.79% 1.04% +0.25%
3 2025-12-27 — 0.79% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20019

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-20019

Affected software / configurations for CVE-2021-20019

Vendor Product Version Raw CPE
sonicwall sonicos >= 7.0.0, < 7.0.0.376 cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
sonicwall sonicos >= 7.0.1, < 7.0.1-r1036 cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
sonicwall sonicos 6.0.5.3-94o cpe:2.3:o:sonicwall:sonicos:6.0.5.3-94o:*:*:*:*:*:*:*
sonicwall sonicos 6.5.1.12-3n cpe:2.3:o:sonicwall:sonicos:6.5.1.12-3n:*:*:*:*:*:*:*
sonicwall sonicos 6.5.4.7-83n cpe:2.3:o:sonicwall:sonicos:6.5.4.7-83n:*:*:*:*:*:*:*
sonicwall sonicosv 6.5.4.4-44v-21-955 cpe:2.3:o:sonicwall:sonicosv:6.5.4.4-44v-21-955:*:*:*:*:*:*:*

References for CVE-2021-20019

cvelogic Threat Intelligence