CVE-2021-20039

Exp

Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

Published: 2021-12-08 Last update: 2025-09-05 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20039 is rated High Exploit Risk (89.9/100): CVSS High severity, with high exploitation likelihood (EPSS 82.46%, 99th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +24.64% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2021-20039

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-20039

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 2025-12-12 57.82% 82.46% +24.64%
2 2025-11-21 76.82% 57.82% -19.00%
3 2025-11-18 — 76.82% —

Full EPSS history (53 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20039

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]
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 134c704f-9b21-4f2e-91b3-4a467353bcc0
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-2021-20039

Affected software / configurations for CVE-2021-20039

Vendor Product Version Raw CPE
sonicwall sma_200_firmware 9.0.0.11-31sv cpe:2.3:o:sonicwall:sma_200_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
sonicwall sma_200_firmware 10.2.0.8-37sv cpe:2.3:o:sonicwall:sma_200_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
sonicwall sma_200_firmware 10.2.1.1-19sv cpe:2.3:o:sonicwall:sma_200_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
sonicwall sma_210_firmware 9.0.0.11-31sv cpe:2.3:o:sonicwall:sma_210_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
sonicwall sma_210_firmware 10.2.0.8-37sv cpe:2.3:o:sonicwall:sma_210_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
sonicwall sma_210_firmware 10.2.1.1-19sv cpe:2.3:o:sonicwall:sma_210_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
sonicwall sma_410_firmware 9.0.0.11-31sv cpe:2.3:o:sonicwall:sma_410_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
sonicwall sma_410_firmware 10.2.0.8-37sv cpe:2.3:o:sonicwall:sma_410_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
sonicwall sma_410_firmware 10.2.1.1-19sv cpe:2.3:o:sonicwall:sma_410_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
sonicwall sma_400_firmware 9.0.0.11-31sv cpe:2.3:o:sonicwall:sma_400_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
sonicwall sma_400_firmware 10.2.0.8-37sv cpe:2.3:o:sonicwall:sma_400_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
sonicwall sma_400_firmware 10.2.1.1-19sv cpe:2.3:o:sonicwall:sma_400_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
sonicwall sma_500v_firmware 9.0.0.11-31sv cpe:2.3:o:sonicwall:sma_500v_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
sonicwall sma_500v_firmware 10.2.0.8-37sv cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
sonicwall sma_500v_firmware 10.2.1.1-19sv cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*

References for CVE-2021-20039

cvelogic Threat Intelligence