Vulnerability Report

CVE-2021-20038

RCE CISA KEV Active

Title: Stack-based buffer overflow in SMA100 Apache httpd server's mod_cgi

RCE

Proof Of Concept

PoC Available for CVE-2021-20038

CWE Category CWE-787
Published Date Dec 08, 2021
Modified Date Oct 31, 2025
Exploit Status Available
Score 9.8 CVSS v3.1
Exploit Probability (EPSS)
99.91%

Vulnerability Summary

CVE-2021-20038: A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attacker to potentially execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv and earlier versions.

Impacted Vendors

S
sonicwall 5

Reference Links

https://github.com/jbaines-r7/badblood https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026 https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/ https://github.com/jbaines-r7/badblood https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026 https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/ https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20038
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v3.1
Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity HIGH
7.5
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:N/C:P/I:P/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-20038 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/jbaines-r7/badblood
View Code
GitHub https://github.com/vesperp/CVE-2021-20038-SonicWall-RCE
View Code
MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.