Actively exploited in the wild
SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
SonicWall - SMA 100 Appliances · Listed in the CISA KEV since 2022-01-28. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2021-20038
CriticalCVSS 9.8KEVSummary
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.
Risk Assessment
An attacker can execute arbitrary code as the 'nobody' user, potentially leading to further privilege escalation and full device compromise. The vulnerability requires no authentication and is easily exploitable remotely.
Recommendation
Upgrade the firmware of SMA 200, 210, 400, 410, and 500v appliances to the latest version containing the fix. If upgrade is not possible, restrict access to the management interface and monitor for unusual activity.
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Original NVD description (English source)
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.