Ca300 Poe FirmwareOperating system · Totolink

CVE-2025-6620

CRITICAL · 9.8 CVSS v3.1 Published 2025-06-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability was found in TOTOLINK CA300-PoE 6.2c.884. It has been rated as critical. Affected by this issue is the function setUpgradeUboot of the file upgrade.so. The manipulation of the argument FileName leads to os command injection. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OS command injection in TOTOLINK CA300-PoE router firmware (v6.2c.884) within the setUpgradeUboot function in upgrade.so. The FileName parameter is not sanitized before being passed to system shell commands, allowing remote attackers to execute arbitrary OS commands via crafted input.

MitigationApply vendor firmware patch when available; immediately restrict network access to the device's management interface and disable remote administration if possible. Implement input validation/allowlisting for the FileName parameter in any interim compensating controls.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Ca300 Poe FirmwareOperating system
Affected:= 6.2c.884

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device model is TOTOLINK CA300-PoE
    Access the router web interface or check device labeling; look for 'CA300-PoE' model identifier in the device info page or physical label
    Affected if Device is NOT a TOTOLINK CA300-PoE router - different models are not affected by this specific CVE
  2. Verify firmware version is exactly 6.2c.884
    Log into the router web interface and navigate to System Status or Firmware Information page; locate the firmware version field
    Affected if Firmware version is NOT 6.2c.884 - only this specific version is listed as affected
  3. Confirm web management interface is accessible
    Attempt to reach the router's web interface via its IP address (typically 192.168.0.1 or 192.168.1.1); verify the login page loads
    Affected if Management interface is completely inaccessible from all network segments - the vulnerability cannot be exploited if there is no interface to interact with
  4. Check if remote WAN administration is enabled
    In the router web interface, navigate to Administration or Remote Management settings; look for options like 'Enable Remote Management' or 'Allow WAN Access'
    Affected if Remote WAN administration is disabled AND the device is not reachable from untrusted networks - this limits the attack surface though the underlying vulnerability still exists in the firmware

The device is affected if it is a TOTOLINK CA300-PoE router running firmware version 6.2c.884 with its management or upgrade interface accessible to the attacker

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware patch when available; immediately restrict network access to the device's management interface and disable remote administration if possible. Implement input validation/allowlisting for the FileName parameter in any interim compensating controls.

Fix this in Ca300 Poe Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-6620 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-6620 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data