What is CVE-2023-40042?

CVE-2023-40042 is a critical-severity vulnerability in Totolink T10 V2, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-08-08.

How severe is CVE-2023-40042?

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

Buffer overflow in Totolink T10 V2

CVE-2023-40042

TOTOLINK T10_v2 5.9c.5061_B20200511 has a stack-based buffer overflow in setStaticDhcpConfig in /lib/cste_modules/lan.so. Attackers can send crafted data in an MQTT packet, via the comment parameter, to control the return address and execute code.

Vulnerability class: Buffer Overflow

Published 2023-08-08 · 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: 0.015 (74.0th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Totolink T10 V2
Totolink T10 V2 Firmware — versions 5.9c.5061_b20200511

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

www.totolink.cn (Not Applicable)
github.com/Korey0sh1/IoT_vuln/blob/main/TOTOLINK/T10_V2/setStaticDhcpConfig.md (Exploit, Third Party Advisory)
www.totolink.net/home/menu/detail/menu_listtpl/download/id/172/ids/36.html (Product)

Frequently asked questions

What is CVE-2023-40042?: CVE-2023-40042 is a critical-severity vulnerability in Totolink T10 V2, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-08-08.
How severe is CVE-2023-40042?: Critical severity. CVSS v3 base score is 9.8 out of 10.