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Vulnerability record · CVE-2021-20040 · published 8 December 2021

CVE-2021-20040: Sonicwall sma 200 firmware relative path traversal vulnerability

Sonicwall · Sma 200 Firmware

A relative path traversal vulnerability in the SMA100 upload funtion allows a remote unauthenticated attacker to upload crafted web pages or files as a 'nobody' user. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

7.5 CVSS 3.1 High EPSS 25% · top 2.1% CWE-23 · Relative path traversalCWE-22 · Path traversal
7.5CVSS 3.1 base score, v2 5.0
25%EPSS exploitation probability, 30 days
NoNot in CISA KEV
5Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A relative path traversal vulnerability in the SMA100 upload funtion allows a remote unauthenticated attacker to upload crafted web pages or files as a 'nobody' user. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

5 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026 Vendor Advisory
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026 Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-20038SonicWall SMA 100 appliances stack buffer overflow in mod_cgiA stack-based buffer overflow in the Apache httpd mod_cgi module of SonicWall SMA 100 series appliances lets a remote unauthenticated attacker overwr…KEVEPSS 100%analysed9.8CVE-2021-20028SonicWall SRA appliances SQL injection in end-of-life firmwareSonicWall Secure Remote Access (SRA) appliances running all 8.x firmware and 9.0.0.9-26sv or earlier fail to neutralize SQL commands, allowing SQL in…KEVEPSS 30%analysed9.8CVE-2021-20016SonicWall SMA100 SSLVPN SQL injection allows unauthenticated accessSonicWall SSLVPN SMA100 firmware 10.x contains a SQL injection flaw in its SSLVPN interface. A remote attacker with no credentials can inject SQL to …KEVEPSS 40%analysed9.1CVE-2024-38475Apache HTTP Server mod_rewrite improper escaping enables code executionApache HTTP Server 2.4.59 and earlier has an improper output escaping flaw in mod_rewrite. Substitutions in server context that use a backreference o…KEVEPSS 100%analysed7.2CVE-2023-44221SonicWall SMA100 SSL-VPN management interface OS command injectionThe SMA100 SSL-VPN management interface fails to neutralize special elements, allowing command injection. A remote attacker who already holds adminis…KEVEPSS 76%analysed6.5CVE-2021-20035SonicWall SMA100 management interface OS command injectionThe SMA100 management interface fails to neutralize special elements, letting a remote authenticated attacker inject arbitrary commands that run as t…KEVEPSS 4.2%analysed9.8CVE-2022-22273Sonicwall sma 200 firmware os command injection vulnerabilityImproper neutralization of Special Elements leading to OS Command Injection vulnerability impacting end-of-life Secure Remote Access (SRA) products a…EPSS 1.9%9.8CVE-2021-20042Sonicwall sma 200 firmware vulnerabilityAn unauthenticated remote attacker can use SMA 100 as an unintended proxy or intermediary undetectable proxy to bypass firewall rules. This vulnerabi…EPSS 2.6%

Source: NIST National Vulnerability Database (record CVE-2021-20040), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.