Buffer overflow in Tenda Ax3

CVE-2021-46393

There is a stack buffer overflow vulnerability in the formSetPPTPServer function of Tenda-AX3 router V16.03.12.10_CN. The v10 variable is directly retrieved from the http request parameter startIp. Then v10 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.

Vulnerability class: Buffer Overflow

EPSS: 0.159 (96.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-46393?
CVE-2021-46393 is a critical-severity vulnerability in Tenda Ax3, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2022-03-04.
How severe is CVE-2021-46393?
Critical severity. CVSS v3 base score is 9.8 out of 10.