Description
A vulnerability was detected in TOTOLINK CA300-PoE 6.2c.884. Affected by this issue is the function UploadCustomModule of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument File results in buffer overflow. The attack may be launched remotely. The exploit is now public and may be used.
Published: 2026-11-07
Score: 9.4 Critical
EPSS: n/a
KEV: No
Impact: Remote Code Execution via buffer overflow
Action: Immediate Patch
AI Analysis

Impact

The vulnerability involves a buffer overflow triggered when the File argument to the UploadCustomModule function in /cgi-bin/cstecgi.cgi is malformed. The overflow can overwrite memory and allow an attacker to execute arbitrary code on the device, which can compromise confidentiality, integrity, and availability of the router and its connected network.

Affected Systems

Affected is the TOTOLINK CA300-PoE product running firmware version 6.2c.884. The flaw exists only in that firmware release; newer or earlier releases may not be impacted. Users with this model should verify their firmware version.

Risk and Exploitability

The CVSS score of 9.4 indicates critical severity. The EPSS score is not available, so the likelihood of exploitation cannot be quantified, but a public exploit is known and can be launched remotely. The defect is not listed in the CISA KEV catalog. Attackers can exploit this flaw remotely via the management interface, sending a crafted upload request that triggers the overflow.

Generated by OpenCVE AI on November 7, 2026 at 21:20 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the device firmware to a release that contains the fix for the buffer overflow or to the latest available version from TOTOLINK.
  • Restrict or disable remote management to eliminate external access to the cstecgi.cgi endpoint.
  • Configure firewall or access control lists to block traffic to /cgi-bin/cstecgi.cgi from untrusted networks.
  • Monitor device logs for anomalous upload attempts and verify that the issue is resolved.

Generated by OpenCVE AI on November 7, 2026 at 21:20 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Sat, 07 Nov 2026 22:00:00 +0000

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

Sat, 07 Nov 2026 20:45:00 +0000

Type Values Removed Values Added
Description A vulnerability was detected in TOTOLINK CA300-PoE 6.2c.884. Affected by this issue is the function UploadCustomModule of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument File results in buffer overflow. The attack may be launched remotely. The exploit is now public and may be used.
Title TOTOLINK CA300-PoE cstecgi.cgi UploadCustomModule 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 Ca300-poe Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-11-07T20:30:18.649Z

Reserved: 2026-11-06T19:53:59.951Z

Link: CVE-2026-124060

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-07T21:17:00.150

Modified: 2026-11-07T21:17:00.397

Link: CVE-2026-124060

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-07T21:45:16Z

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')