What is CVE-2021-40546?

CVE-2021-40546 is a medium-severity vulnerability in Tenda Ac6, classified under Improper Resource Shutdown or Release. CVSS score: 4.9/10. Published 2023-09-05.

How severe is CVE-2021-40546?

Medium severity. CVSS v3 base score is 4.9 out of 10.

Vulnerability in Tenda Ac6

CVE-2021-40546

Tenda AC6 US_AC6V4.0RTL_V02.03.01.26_cn.bin allows attackers (who have the administrator password) to cause a denial of service (device crash) via a long string in the wifiPwd_5G parameter to /goform/setWifi.

Published 2023-09-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (52.7th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Tenda Ac6 — versions 4.0
Tenda Ac6 Firmware — versions 02.03.01.26

Weakness classification (CWE)

CWE-404 — Improper Resource Shutdown or Release

References

github.com/doudoudedi/buffer_overflow/blob/main/Tenda AC6 V4.0-Denial of Servic… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-40546?: CVE-2021-40546 is a medium-severity vulnerability in Tenda Ac6, classified under Improper Resource Shutdown or Release. CVSS score: 4.9/10. Published 2023-09-05.
How severe is CVE-2021-40546?: Medium severity. CVSS v3 base score is 4.9 out of 10.