CVEs / CVE-2021-20038
CVE-2021-20038: SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
- Known exploited in the CISA KEV catalog since 28 Jan 2022
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 99.9% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
SonicWall SMA 100 devies are vulnerable to an unauthenticated stack-based buffer overflow vulnerability where exploitation can result in code execution.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| SonicWall SonicWall SMA100 | 10.2.0.8-37sv and earlier | — |
| SonicWall SonicWall SMA100 | 10.2.1.1-19sv and earlier | — |
| SonicWall SonicWall SMA100 | 10.2.1.2-24sv and earlier | — |
Exploitation
| In CISA KEV since | 28 Jan 2022 |
|---|---|
| Due date for US federal agencies | 11 Feb 2022 |
| Used in ransomware campaigns | Known |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-121, CWE-787 |
References
- CVE-2021-20038 on NVD
- CVE-2021-20038 in the CISA KEV catalog
- https://github.com/jbaines-r7/badblood Exploit, Third Party Advisory
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026 Vendor Advisory
- https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/ Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20038 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.