September 22, 2023
Hackers Exploiting Critical Zero-Day Bug in SonicWall SMA 100 Devices

SonicWall urges customers using SMA 100 series appliances to apply security patches that address multiple security vulnerabilities, some of which have been rated as critical.


SonicWall has verified and patched vulnerabilities of critical and medium severity (CVSS 5.3-9.8) in SMA 100 series appliances, which include SMA 200, 210, 400, 410 and 500v products. SMA 100 series appliances with WAF enabled are also impacted by most of these vulnerabilities

Affected products are SMA 200, 210, 400, 410, and 500v appliances.

The most severe vulnerabilities addressed by SonicWall are two critical stack-based buffer overflow vulnerabilities tracked as CVE-2021-20038 and CVE-2021-20045 respectively. A remote attacker can trigger the two vulnerabilities to potentially execute as the ‘nobody’ user in compromised appliances.

“A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server’s mod_cgi module environment variables allow 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,, and earlier versions.” reads the advisory for the CVE-2021-20038 flaw.


SonicWall is not aware of attacks in the wild exploiting the following vulnerabilities.

Issue IDSummaryCVECVSS
SMA-3217Unauthenticated Stack-Based Buffer OverflowCVE-2021-200389.8
SMA-3204Authenticated Command InjectionCVE-2021-200397.2
SMA-3206Unauthenticated File Upload Path TraversalCVE-2021-200406.5
SMA-3207Unauthenticated CPU ExhaustionCVE-2021-200417.5
SMA-3208Unauthenticated Confused DeputyCVE-2021-200426.3
SMA-3231Heap-Based Buffer OverflowCVE-2021-200438.8
SMA-3233Post-Authentication Remote Command ExecutionCVE-2021-200447.2
SMA-3235Multiple Unauthenticated Heap-Based and Stack Based Buffer OverflowCVE-2021-200459.4

Leave a Reply

%d bloggers like this: