Actively exploited in the wild
Tenda AC11 Router Stack Buffer Overflow Vulnerability
Tenda - AC11 Router · Listed in the CISA KEV since 2021-11-03. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2021-31755
CriticalCVSS 9.8KEVSummary
A stack buffer overflow vulnerability exists in /goform/setmac on Tenda AC11 devices with firmware through 02.03.01.104_CN. It allows attackers to execute arbitrary code via a crafted POST request.
Risk Assessment
A remote attacker could execute arbitrary code on the Tenda AC11 device, potentially taking control of the router and all network traffic.
Recommendation
Update the Tenda AC11 firmware to a version newer than 02.03.01.104_CN if available. Otherwise, consider replacing the device or restricting access to the management interface.
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Original NVD description (English source)
An issue was discovered on Tenda AC11 devices with firmware through 02.03.01.104_CN. A stack buffer overflow vulnerability in /goform/setmac allows attackers to execute arbitrary code on the system via a crafted post request.