Cyber Posture

CVE-2025-12241

HighPublic PoC

Published: 27 October 2025

Published
27 October 2025
Modified
28 October 2025
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0039 60.0th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

Security Summary

CVE-2025-12241 is a stack-based buffer overflow vulnerability in the TOTOLINK A3300R router running firmware version 17.0.0cu.557_B20221024. The issue affects the setLanguageCfg function within the /cgi-bin/cstecgi.cgi file, specifically the POST Parameter Handler component, where manipulation of the 'lang' argument triggers the overflow. Associated with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow), it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

The vulnerability enables remote exploitation by an attacker with low privileges, such as an authenticated user on the network. By sending a specially crafted POST request manipulating the 'lang' parameter, the attacker can overflow the stack, potentially leading to arbitrary code execution, data corruption, or denial of service, with high impacts on confidentiality, integrity, and availability.

Advisories from VulDB (ctiid.329911, id.329911, submit.673723) document the issue and note that an exploit is publicly available on GitHub at https://github.com/noahze01/IoT-vulnerable/blob/main/TOTOLink/A3300R/setLanguageCfg.md, increasing the risk of active use. The vendor's site at https://www.totolink.net/ provides general support resources, but no specific patch details are outlined in the provided references.

The exploit's public availability heightens the urgency for affected users to monitor and update firmware where possible.

Details

CWE(s)
CWE-119CWE-121

Affected Products

totolink
a3300r firmware
17.0.0cu.557_b20221024

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Stack-based buffer overflow in the router's web CGI interface (/cgi-bin/cstecgi.cgi) via POST parameter allows remote exploitation of a public-facing application.

References