# CVE-2021-20038: SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability

> CVE-2021-20038: SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2021-20038
Last updated: 2025-10-21T23:25:23Z

- Published: 2021-12-08 09:55 UTC · Updated: 2025-10-21 23:25 UTC · Assigner: sonicwall
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 99.9%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2022-01-28, federal due date 2022-02-11, ransomware use: Known
- CWE: CWE-121

## Description

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.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- SonicWall: SonicWall SMA100

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-20038)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2021-20038)
- [https://github.com/jbaines-r7/badblood](https://github.com/jbaines-r7/badblood)
- [https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026](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.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2021-20038 · Markdown: https://rewindex.com/cve/CVE-2021-20038.md · JSON: https://rewindex.com/api/v1/cves/CVE-2021-20038 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:20.356Z