CVE-2021-20038A 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' use…
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It affects SonicWall SMA100 and 5 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Jan 28, 2022; federal agencies had to remediate by Feb 11, 2022, and it is known to be used in ransomware. Treat that date as your deadline.
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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
- 9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-121
- Known exploited
- Added to CISA KEV Jan 28, 2022; federal remediation due Feb 11, 2022; known ransomware useApply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 99.91% (percentile 100)
- Assigned by
- sonicwall
- NVD analysis
- Analyzed
- Record last updated
- Oct 21, 2025
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
SonicWall SonicWall SMA100 sonicwall:sma100 (from the name) | 10.2.0.8-37sv and earlier; 10.2.1.1-19sv and earlier; 10.2.1.2-24sv and earlier | CNA record |
sonicwall sma_200_firmware sonicwall:sma_200_firmware | 10.2.0.8-37sv; 10.2.1.1-19sv; 10.2.1.2-24sv | NVD |
sonicwall sma_210_firmware sonicwall:sma_210_firmware | 10.2.0.8-37sv; 10.2.1.1-19sv; 10.2.1.2-24sv | NVD |
sonicwall sma_410_firmware sonicwall:sma_410_firmware | 10.2.0.8-37sv; 10.2.1.1-19sv; 10.2.1.2-24sv | NVD |
sonicwall sma_400_firmware sonicwall:sma_400_firmware | 10.2.0.8-37sv; 10.2.1.1-19sv; 10.2.1.2-24sv | NVD |
sonicwall sma_500v_firmware sonicwall:sma_500v_firmware | 10.2.0.8-37sv; 10.2.1.1-19sv; 10.2.1.2-24sv | NVD |
References
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026x-refsource-confirm, vendor-advisory
- https://github.com/jbaines-r7/badbloodx-refsource-misc, exploit, third-party-advisory
- https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/x-refsource-misc, exploit, third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20038us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.