CVE DATABASE / CVE-2021-20038
CVE-2021-20038
SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
Confirmed exploited in the wild. Added 2022-01-28.
Federal remediation due 2022-02-11.
Required action: Apply updates per vendor instructions.
Summary
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.
CVSS 3.1 breakdown
| Base score | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity | HIGH |
| Availability | HIGH |
Weakness type (CWE)
Affected products
Use our free CVE Lookup tool for the latest NVD record, or browse the full CISA KEV catalog.
References
- 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
Data: NIST NVD + CISA KEV. NVD last modified 2025-10-31. Always verify against the vendor advisory before acting.