Description
A weakness has been identified in TOTOLINK CA300-PoE 6.2c.884. Affected is the function setWiFiRepeaterConfig of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument ApCliKeyStr can lead to buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks.
Published: 2026-11-07
Score: 9.4 Critical
EPSS: n/a
KEV: No
Impact: Remote Code Execution
Action: Patch Immediately
AI Analysis

Impact

An unbounded buffer write occurs in the setWiFiRepeaterConfig function of the /cgi-bin/cstecgi.cgi script when the ApCliKeyStr argument is processed. The overflow can be triggered without authentication and may allow an attacker to inject arbitrary code into the router’s memory, effectively taking control of the device. The vulnerability is a classic stack buffer overflow (CWE-119) combined with improper pointer handling (CWE-120).

Affected Systems

The flaw is confirmed in TOTOLINK CA300‑PoE routers running firmware version 6.2c.884. No other firmware releases have been documented as affected, but any device running the same code base should be checked. The vulnerability resides exclusively in this router model and its associated CGI script.

Risk and Exploitability

The CVSS score of 9.4 demonstrates a critical severity with full impact on confidentiality, integrity, and availability. EPSS is not available, yet public exploits have already been disclosed, indicating a tangible threat. The vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that the attacker can launch the exploit remotely by sending a crafted HTTP request to cstecgi.cgi containing an oversized ApCliKeyStr payload, thus exercising a remote code execution vector.

Generated by OpenCVE AI on November 7, 2026 at 19:20 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the router firmware to a version that patches the setWiFiRepeaterConfig buffer overflow.
  • If a patch is not yet available, disable the WiFi repeater feature or block external access to /cgi-bin/cstecgi.cgi via the router’s firewall or access control lists.
  • Restrict administration of the router to trusted local networks and consider using a VPN or secure management gateway to isolate the device from untrusted traffic.

Generated by OpenCVE AI on November 7, 2026 at 19:20 UTC.

Tracking

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Advisories

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History

Sat, 07 Nov 2026 18:30:00 +0000

Type Values Removed Values Added
Description A weakness has been identified in TOTOLINK CA300-PoE 6.2c.884. Affected is the function setWiFiRepeaterConfig of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument ApCliKeyStr can lead to buffer overflow. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks.
Title TOTOLINK CA300-PoE cstecgi.cgi setWiFiRepeaterConfig buffer overflow
First Time appeared Totolink
Totolink ca300-poe Firmware
Weaknesses CWE-119
CWE-120
CPEs cpe:2.3:o:totolink:ca300-poe_firmware:*:*:*:*:*:*:*:*
Vendors & Products Totolink
Totolink ca300-poe Firmware
References
Metrics cvssV2_0

{'score': 8.3, 'vector': 'AV:N/AC:L/Au:M/C:C/I:C/A:C/E:POC/RL:ND/RC:C'}

cvssV3_0

{'score': 9.1, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C'}

cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C'}

cvssV4_0

{'score': 9.4, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P'}

Subscriptions

Totolink Ca300-poe Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-11-07T18:15:13.457Z

Reserved: 2026-11-06T19:53:52.566Z

Link: CVE-2026-124058

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-07T19:17:28.263

Modified: 2026-11-07T19:17:28.427

Link: CVE-2026-124058

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-07T19:30:07Z

Weaknesses
  • CWE-119

    Improper Restriction of Operations within the Bounds of a Memory Buffer

  • CWE-120

    Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')