What is CVE-2023-40942?

CVE-2023-40942 is a critical-severity vulnerability in Tendacn Ac9, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-09-07.

How severe is CVE-2023-40942?

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

Buffer overflow in Tendacn Ac9

CVE-2023-40942

Tenda AC9 V3.0BR_V15.03.06.42_multi_TD01 was discovered stack overflow via parameter 'firewall_value' at url /goform/SetFirewallCfg.

Vulnerability class: Buffer Overflow

Published 2023-09-07 · 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: 0.008 (56.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.2% 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: 0.008 · change: +0.001

Affected products

Tendacn Ac9 — versions 3.0
Tendacn Ac9 Firmware — versions 15.03.06.42_multi_td0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/GleamingEyes/vul/blob/main/tenda_ac9/SetFirewallCfg.md (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2023-40942?: CVE-2023-40942 is a critical-severity vulnerability in Tendacn Ac9, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-09-07.
How severe is CVE-2023-40942?: Critical severity. CVSS v3 base score is 9.8 out of 10.