What is CVE-2020-13392?

CVE-2020-13392 is a critical-severity vulnerability in Tendacn Ac15, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2020-05-22.

How severe is CVE-2020-13392?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Tendacn Ac15

CVE-2020-13392

An issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.19_multi_TD01, and AC18 V15.03.05.19(6318_)_CN devices. There is a buffer overflow vulnerability in the router's web server -- httpd. While processing the /goform/setcfm funcpara1 parameter for a POST request, a value is directly used in a sprintf to a local variable placed on the stack, which overwrites the return address of a function. An attacker can construct a payload to carry out arbitrary code execution attacks.

Vulnerability class: Buffer Overflow

Published 2020-05-22 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.026 (84.4th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.026 · newest: 0.026 · change: 0.000

Affected products

Tendacn Ac15 — versions 1.0
Tendacn Ac15 Firmware — versions v15.03.05.19_multi_td01
Tendacn Ac18
Tendacn Ac18 Firmware — versions v15.03.05.19(6318), v15.03.05.19\(6318\)
Tendacn Ac6 — versions 1.0
Tendacn Ac6 Firmware — versions v15.03.05.19_multi_td01
Tendacn Ac9 — versions 1.0, 3.0
Tendacn Ac9 Firmware — versions v15.03.06.42_multi, v15.03.05.19(6318), v15.03.05.19\(6318\)

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

joel-malwarebenchmark.github.io (Exploit, Third Party Advisory)
joel-malwarebenchmark.github.io/blog/2020/04/28/cve-2020-13392-Tenda-vulnerabil… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2020-13392?: CVE-2020-13392 is a critical-severity vulnerability in Tendacn Ac15, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2020-05-22.
How severe is CVE-2020-13392?: Critical severity. CVSS v3 base score is 9.8 out of 10.