CVE-2020-13391

CRITICAL

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/SetSpeedWan speed_dir 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.

Published: May 22, 2020 Modified: Jun 17, 2026

CWE-120

CVSS Metrics

CVSSv3

Attack Vector: NETWORK Attack Complexity: LOW Privileges Required: NONE User Interaction: NONE Scope: UNCHANGED Confidentiality Impact: HIGH Integrity Impact: HIGH Availability Impact: HIGH

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

Affected Products (5)

Vendor	Product	Version
tendacn	ac6_firmware	v15.03.05.19_multi_td01
tendacn	ac9_firmware	v15.03.05.19\(6318\)
tendacn	ac15_firmware	v15.03.05.19_multi_td01
tendacn	ac18_firmware	v15.03.05.19\(6318\)
tendacn	ac9_firmware	v15.03.06.42_multi

GitHub Security Advisory GHSA-v393-hrm3-64jv

An issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN...

References (4)

https://joel-malwarebenchmark.github.io Exploit, Third Party Advisory
https://joel-malwarebenchmark.github.io/blog/2020/04/28/cve-2020-13391-Tenda-vulnerability/ Exploit, Third Party Advisory
https://joel-malwarebenchmark.github.io Exploit, Third Party Advisory
https://joel-malwarebenchmark.github.io/blog/2020/04/28/cve-2020-13391-Tenda-vulnerability/ Exploit, Third Party Advisory

Risk Scores

CVSS Score 9.8 / 10

EPSS Score 2.55%

Top 16% most likely to be exploited

Threat Score 40 / 100

Data Sources

NVD EPSS GitHub