Description
A vulnerability was determined in TOTOLINK CA300-PoE 6.2c.884. Impacted is the function setIpQosRules of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument ipStart causes buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized.
Published: 2026-11-07
Score: 9.4 Critical
EPSS: n/a
KEV: No
Impact: Remote Code Execution
Action: Patch Immediately
AI Analysis

Impact

A buffer overflow exists in the setIpQosRules function of /cgi-bin/cstecgi.cgi on TOTOLINK CA300-PoE. Manipulating the ipStart argument can overflow a local buffer, allowing an attacker to overwrite executable code or data on the device. The flaw is exploitable from a remote connection, making it a high‑risk vulnerability that could lead to arbitrary code execution or denial of service.

Affected Systems

The affected product is TOTOLINK CA300‑PoE running firmware 6.2c.884. The vulnerability is specific to that model and version; other firmware revisions or brands are not listed as affected.

Risk and Exploitability

The CVSS score is 9.4, indicating critical severity. EPSS data is not available, but the vulnerability is publicly disclosed and reported as usable, so the likelihood of exploitation is considered high. The vulnerability is not listed in CISA KEV yet, although vendors and community resources confirm it is being exploited. Likely attack via the exposed HTTP endpoint that processes setIpQosRules.

Generated by OpenCVE AI on November 7, 2026 at 09:20 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the router firmware to the latest version released by TOTOLINK for the CA300-PoE model.
  • Restrict remote access to the CGI endpoint by firewall rules or by enabling only local management and blocking external IP ranges.
  • If a patch is not yet available, disable or limit the /cgi-bin/cstecgi.cgi functionality via firewall or router configuration to prevent remote manipulation of ipStart.

Generated by OpenCVE AI on November 7, 2026 at 09:20 UTC.

Tracking

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Advisories

No advisories yet.

History

Sat, 07 Nov 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Totolink ca300-poe
Vendors & Products Totolink ca300-poe

Sat, 07 Nov 2026 08:30:00 +0000

Type Values Removed Values Added
Description A vulnerability was determined in TOTOLINK CA300-PoE 6.2c.884. Impacted is the function setIpQosRules of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument ipStart causes buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized.
Title TOTOLINK CA300-PoE cstecgi.cgi setIpQosRules 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': 9, 'vector': 'AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:C'}

cvssV3_0

{'score': 9.9, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C'}

cvssV3_1

{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/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:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P'}

Subscriptions

Totolink Ca300-poe Ca300-poe Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-11-07T08:15:13.072Z

Reserved: 2026-11-06T17:07:11.931Z

Link: CVE-2026-123957

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-07T09:17:14.890

Modified: 2026-11-07T09:17:15.120

Link: CVE-2026-123957

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-07T09:30:12Z

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')