CVE-2021-20026

A vulnerability in the SonicWall NSM On-Prem product allows an authenticated attacker to perform OS command injection using a crafted HTTP request. This vulnerability affects NSM On-Prem 2.2.0-R10 and earlier versions.

Published: 2021-05-27 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20026 is rated High Risk (73.6/100): CVSS High severity, with high exploitation likelihood (EPSS 11.64%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +8.86% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize 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-2021-20026

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 2.78% 11.64% +8.86%
2 2026-01-02 2.20% 2.78% +0.58%
3 2025-11-21 — 2.20% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20026

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
9.0 2.0 HIGH
AV:N/AC:L/Au:S/C:C/I:C/A:C 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:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.0 10.0 [email protected]

Weakness enumeration for CVE-2021-20026

Affected software / configurations for CVE-2021-20026

Vendor Product Version Raw CPE
sonicwall network_security_manager < 2.2.0 cpe:2.3:a:sonicwall:network_security_manager:*:*:*:*:on-premises:*:*:*
sonicwall network_security_manager 2.2.0 cpe:2.3:a:sonicwall:network_security_manager:2.2.0:-:*:*:on-premises:*:*:*
sonicwall network_security_manager 2.2.0 cpe:2.3:a:sonicwall:network_security_manager:2.2.0:r10:*:*:on-premises:*:*:*

References for CVE-2021-20026

cvelogic Threat Intelligence