Vigor3900 FirmwareOperating system · Draytek

CVE-2024-51246

HIGH · 8.0 CVSS v3.1 Published 2024-11-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
82/100
Remediation priority · High
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
In Draytek Vigor3900 1.5.1.3, attackers can inject malicious commands into mainfunction.cgi and execute arbitrary commands by calling the doPPTP function.

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

Command injection vulnerability in Draytek Vigor3900 version 1.5.1.3 allows remote attackers to execute arbitrary operating system commands by injecting malicious input into the doPPPTP function within mainfunction.cgi. The vulnerability stems from insufficient input sanitization on the PPTP-related parameter(s), enabling OS command execution with the privileges of the web server.

MitigationRestrict network access to the Vigor3900 management interface; implement strict input validation and avoid passing user-supplied data to shell commands; contact Draytek for an official firmware patch.

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
Vigor3900 FirmwareOperating system
Affected:= 1.5.1.3

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
Adjacent
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/AC:L/PR:L/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. Identify the device model
    Access the router admin interface or check the device label/metadata to confirm it is a Draytek Vigor3900
    Affected if The device is not a Draytek Vigor3900 (not affected)
  2. Check the installed firmware version
    Navigate to the router admin panel (typically System > Maintenance or Firmware Upgrade) and locate the firmware version information, or use the command line interface if available
    Affected if The firmware version is exactly 1.5.1.3 (this version is affected)
  3. Verify PPTP/PPPTP functionality status
    In the router admin interface, go to VPN and Remote Access settings or similar menu to determine whether PPTP (Point-to-Point Tunneling Protocol) is enabled or configured
    Affected if PPTP is enabled or configured (the vulnerable doPPPTP function can be triggered)
  4. Confirm mainfunction.cgi accessibility
    Check if the web interface is accessible remotely (via WAN) or if remote management is enabled for mainfunction.cgi; attempt to access the CGI endpoint or review access control settings
    Affected if Remote management allows access to mainfunction.cgi (exposure vector exists)

A Draytek Vigor3900 with firmware version 1.5.1.3 that has PPTP enabled and mainfunction.cgi accessible remotely is affected by this command injection vulnerability.

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

Restrict network access to the Vigor3900 management interface; implement strict input validation and avoid passing user-supplied data to shell commands; contact Draytek for an official firmware patch.

Fix this in Vigor3900 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
25.0 hours of engineering $4,400
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2024-51246 in production — separate from our analysis above.

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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
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