Vigor3910 FirmwareOperating system · Draytek

CVE-2024-46586

HIGH · 7.5 CVSS v3.1 Published 2024-09-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
Draytek Vigor 3910 v4.3.2.6 was discovered to contain a buffer overflow in the sCloudPass parameter at v2x00.cgi. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted input.

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 · moderate confidence

A buffer overflow vulnerability exists in the sCloudPass parameter of the v2x00.cgi script on Draytek Vigor 3910 firmware v4.3.2.6. Attackers can send specially crafted input exceeding expected buffer boundaries, causing the device to crash and resulting in a Denial of Service condition.

MitigationApply the vendor-supplied firmware patch for CVE-2024-46586. If no patch is available, consider disabling the affected v2x00.cgi endpoint or implementing network-level filtering to restrict unauthenticated access to the web interface.

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
Vigor3910 FirmwareOperating system
Affected:= 4.3.2.6

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Identify device model
    Access the device web interface or check the administrative console to confirm the device is a Draytek Vigor 3910. This can typically be found in the system status or device information page.
    Affected if The device is not a Draytek Vigor 3910, then it is not affected by this specific CVE.
  2. Check firmware version
    Navigate to the device web interface (usually at https://<device-ip>/) and locate the firmware version in System > Status or System Maintenance > Firmware Upgrade. Alternatively, log into the CLI and run 'sys show info' or 'version' to retrieve the firmware build.
    Affected if The installed firmware version is exactly 4.3.2.6, then the device is affected by this vulnerability.
  3. Verify v2x00.cgi endpoint accessibility
    Attempt to access the v2x00.cgi script via HTTP or HTTPS request to the device (e.g., http://<device-ip>/v2x00.cgi). Check if the endpoint responds or requires authentication. This can be done with a simple curl command: curl -I http://<device-ip>/v2x00.cgi
    Affected if The v2x00.cgi endpoint is accessible without authentication or responds to requests, the vulnerability is potentially exploitable.
  4. Review system logs for crashes
    Access the device web interface and navigate to System > Logs or System Maintenance > Diagnostic Options to review system logs. Look for entries indicating v2x00.cgi crashes, process failures, or unexpected reboots.
    Affected if Logs show repeated crashes of v2x00.cgi or unexplained device reboots, this may indicate exploitation attempts.
  5. Check for unusual network behavior
    Monitor network traffic to and from the device using packet capture tools (tcpdump, Wireshark). Look for repeated or automated POST requests to v2x00.cgi with unusually long sCloudPass parameter values.
    Affected if Repeated requests to v2x00.cgi with oversized sCloudPass parameters are observed in network traffic, exploitation may have occurred.

The device is affected only if it is a Draytek Vigor 3910 running firmware version 4.3.2.6 and the v2x00.cgi endpoint is accessible.

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 the vendor-supplied firmware patch for CVE-2024-46586. If no patch is available, consider disabling the affected v2x00.cgi endpoint or implementing network-level filtering to restrict unauthenticated access to the web interface.

Fix this in Vigor3910 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,600
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,160.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-46586 — 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-2024-46586 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