What is CVE-2025-12239?

CVE-2025-12239 is a high-severity vulnerability in Totolink A3300r, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 8.8/10. Published 2025-10-27.

How severe is CVE-2025-12239?

High severity. CVSS v3 base score is 8.8 out of 10.

Buffer overflow in Totolink A3300r

CVE-2025-12239

A weakness has been identified in TOTOLINK A3300R 17.0.0cu.557_B20221024. The impacted element is the function setDdnsCfg of the file /cgi-bin/cstecgi.cgi. Executing manipulation can lead to buffer overflow. The attack may be performed fro…

Vulnerability class: Buffer Overflow

EPSS: 0.004 (62.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R.

Affected products

Totolink A3300r — versions 17.0.0cu.557_B20221024

Weakness classification (CWE)

References

VDB-329909 | TOTOLINK A3300R cstecgi.cgi setDdnsCfg buffer overflow (vdb-entry, technical-description)
VDB-329909 | CTI Indicators (IOB, IOC, IOA) (signature, permissions-required)
Submit #673721 | TOTOLINK A3300R V17.0.0cu.557_B20221024 Buffer Overflow (third-party-advisory)
github.com/noahze01/IoT-vulnerable/blob/main/TOTOLink/A3300R/setDdnsCfg.md (exploit)
www.totolink.net/ (product)

Frequently asked questions

What is CVE-2025-12239?: CVE-2025-12239 is a high-severity vulnerability in Totolink A3300r, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 8.8/10. Published 2025-10-27.
How severe is CVE-2025-12239?: High severity. CVSS v3 base score is 8.8 out of 10.