Rt Ac66u FirmwareOperating system · Asus

CVE-2013-4656

CRITICAL · 9.8 CVSS v3.1 Published 2019-11-13
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
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
Symlink Traversal vulnerability in ASUS RT-AC66U and RT-N56U due to misconfiguration in the SMB service.

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 symlink traversal vulnerability exists in the SMB service of ASUS RT-AC66U and RT-N56U routers due to misconfiguration. This allows remote attackers to traverse symlinks and access arbitrary files on the device filesystem via the SMB protocol, potentially exposing sensitive configuration data, credentials, or other system files.

MitigationApply available firmware updates from ASUS for the affected router models. If no update is available, consider disabling the SMB service or restricting network access to trusted users.

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
Rt Ac66u FirmwareOperating system
Affected:all versions
Rt N56u FirmwareOperating system
Affected:all versions

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. Identify router model
    Access the router's web administration interface (typically at 192.168.1.1) and check the device info page, or log into the router via CLI and run 'nvram get model' or check the device label on the router hardware
    Affected if The router model is ASUS RT-AC66U or RT-N56U
  2. Verify SMB service is enabled
    Log into the router's web interface, navigate to USB/Storage settings or SMB configuration, and check if the SMB file sharing service is turned on
    Affected if SMB service is enabled on the router
  3. Confirm firmware version
    In the router's web interface, go to Firmware Version or Administration > Firmware Upgrade section to view the installed firmware build number
    Affected if Any firmware version is installed on an affected model (all versions are vulnerable)
  4. Assess SMB network exposure
    Check if the SMB service is accessible from the WAN/internet side or from untrusted networks by reviewing access control settings in the router's SMB configuration
    Affected if SMB service is accessible from untrusted network segments

If the router is an ASUS RT-AC66U or RT-N56U with SMB service enabled, the device is affected by this vulnerability regardless of firmware version.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply available firmware updates from ASUS for the affected router models. If no update is available, consider disabling the SMB service or restricting network access to trusted users.

Recommended fix Moderate confidence

These legacy routers are end-of-life with no further firmware releases. Replace with a currently-supported router model.

  1. These ASUS RT-AC66U and RT-N56U routers from 2013 are end-of-life and no longer receive firmware updates from ASUS.
  2. Disable the SMB service on the router through the web interface under USB & Networking settings.
  3. If SMB is required, ensure SMB signing is enforced and restrict access to local network only.
  4. Consider replacing these legacy devices with currently-supported routers that receive regular security updates.
Caveat Replacing these 2013-era routers with modern hardware will require reconfiguration of any devices depending on the old router's SMB or network settings.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Rt Ac66u Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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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-2013-4656 in production — separate from our analysis above.

No notes yet

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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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