Xfinity Wifi HotspotApplication · Comcast

CVE-2017-9475

MEDIUM · 5.9 CVSS v3.0 Published 2017-07-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
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
Comcast XFINITY WiFi Home Hotspot devices allow remote attackers to spoof the identities of Comcast customers via a forged MAC address.

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

The vulnerability exists in Comcast XFINITY WiFi Home Hotspot devices, where insufficient MAC address authentication allows remote attackers to forge MAC addresses and impersonate legitimate Comcast customers on the network.

MitigationComcast should implement MAC address validation and authentication mechanisms at the network level, and push firmware updates to affected hotspot devices to prevent MAC spoofing attacks.

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
Xfinity Wifi HotspotApplication
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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

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 Xfinity WiFi Home Hotspot devices on your network
    Scan your network for devices with manufacturer OUI matching Comcast residential gateways (e.g., 00:1D:D8, 00:1A:8A, 34:6B:D0) or log into your network management system to list connected access points
    Affected if Comcast Xfinity residential gateway devices are present on the network and broadcasting as public WiFi hotspots
  2. Confirm the WiFi hotspot feature is enabled
    Log into the Comcast residential gateway admin interface or use a WiFi scanner to detect secondary SSIDs such as 'xfinity' or 'XFINITY' in addition to the private network
    Affected if The device broadcasts a public hotspot SSID alongside the private network SSID, indicating the hotspot feature is active
  3. Check for MAC address spoofing indicators
    Review network authentication and DHCP logs for MAC addresses that appear to change rapidly or exhibit suspicious authentication patterns from the same IP address
    Affected if Logs show MAC address inconsistencies, multiple MAC addresses authenticating from a single device, or unexpected device authentication failures indicating spoofing is occurring
  4. Verify MAC address authentication enforcement
    Inspect network infrastructure (RADIUS server, controller, or gateway) for MAC address filtering, validation, or authentication policies applied to hotspot traffic
    Affected if No MAC address validation, certificate-based authentication, or client isolation is configured on the hotspot network segment

You are affected if you operate or are connected to Comcast Xfinity residential gateway devices with the WiFi hotspot feature enabled and without MAC address authentication controls in place.

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

Comcast should implement MAC address validation and authentication mechanisms at the network level, and push firmware updates to affected hotspot devices to prevent MAC spoofing attacks.

Fix this in Xfinity Wifi Hotspot Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,400
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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-2017-9475 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data