Cyber Posture

CVE-2025-12259

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 0.0043 62.3th 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-2025-12259 is a stack-based buffer overflow vulnerability affecting the TOTOLINK A3300R router on firmware version 17.0.0cu.557_B20221024. The issue lies in the setScheduleCfg function within the /cgi-bin/cstecgi.cgi file, part of the POST Parameter Handler component, where manipulation of the recHour argument triggers the overflow.

The vulnerability enables remote exploitation over the network with low complexity and low privileges required (PR:L), without user interaction (UI:N). Per its CVSS 3.1 score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), successful attacks can result in high impacts to confidentiality, integrity, and availability, associated with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow).

Advisories reference a published exploit on GitHub at https://github.com/noahze01/IoT-vulnerable/blob/main/TOTOLink/A3300R/setScheduleCfg.md, along with VulDB entries (https://vuldb.com/?ctiid.329930, https://vuldb.com/?id.329930, https://vuldb.com/?submit.673726) and the vendor site https://www.totolink.net/. The exploit is available for use, but no specific patches or mitigations are detailed in the provided references.

Notable context includes the public availability of the exploit, indicating heightened risk for real-world exploitation against unpatched TOTOLINK A3300R devices.

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 remotely accessible web CGI endpoint (/cgi-bin/cstecgi.cgi setScheduleCfg via recHour POST parameter) enables remote code execution, aligning with exploitation of a public-facing application.

References