CVE-2021-46394

9.8 criticalEPSS 2.7%

Critical (9.8) in tenda ax3 firmware. EPSS 2.7% chance of exploitation in the next 30 days.

There is a stack buffer overflow vulnerability in the formSetPPTPServer function of Tenda-AX3 router V16.03.12.10_CN. The v13 variable is directly retrieved from the http request parameter startIp. Then v13 will be splice to stack by function sscanf without any security check, which causes stack overflow. By POSTing the page /goform/SetPptpServerCfg with proper startIp, the attacker can easily perform remote code execution with carefully crafted overflow data.

Severity

CVSS 3.1

9.8 critical

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

EPSS: 2.7% chance of exploitation in the next 30 days; higher than 86% of CVEs (scores of 2026-10-31)
CWE: CWE-787
Published: 2022-03-04
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

tenda:ax3_firmware

References

https://github.com/sec-bin/IoT-CVE/tree/main/Tenda/AX3/4
https://github.com/sec-bin/IoT-CVE/tree/main/Tenda/AX3/4

Check your stack JSON