CVE-2013-4874
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 · uneditedThe Uboot bootloader on the Verizon Wireless Network Extender SCS-26UC4 allows physically proximate attackers to obtain root access by connecting a crafted HDMI cable and using a sys session to modify the ramboot environment variable.
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 confidenceThe Uboot bootloader on the Verizon Wireless Network Extender SCS-26UC4 contains a vulnerability allowing physically proximate attackers to obtain root access by connecting a crafted HDMI cable and using an unauthenticated sys session to modify the ramboot environment variable, enabling arbitrary code execution at boot.
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= scs-26uc4CVSS 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
- Local
- Complexity
- High
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/AC:H/Au:N/C:C/I:C/A:C
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 checksWork through these to decide whether this CVE applies to you.
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Identify the device modelLocate the model number label on the Network Extender device and verify it reads 'SCS-26UC4'Affected if The device model is Verizon Wireless Network Extender SCS-26UC4
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Check for HDMI debug interface accessibilityExamine whether the HDMI port exposes a debug or sys session interface that accepts connections without authenticationAffected if An unauthenticated sys session is available via HDMI
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Inspect the Uboot environment configurationAccess the Uboot bootloader environment (typically via console/HDMI debug) and examine the ramboot variable configurationAffected if The ramboot environment variable can be modified without authentication
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Verify physical HDMI access is possibleConfirm that the HDMI port is physically accessible and not secured behind a locked enclosure or restricted areaAffected if A physically proximate attacker can connect a device to the HDMI port
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Check if HDMI sys session requires authenticationAttempt to access or inspect the sys session via HDMI to determine if a password or other authentication is requiredAffected if The sys session is unauthenticated and accepts commands without credentials
A user is affected if they have a Verizon Wireless Network Extender SCS-26UC4 with an unauthenticated HDMI debug/sys session that allows modification of the Uboot ramboot environment variable, enabling arbitrary code execution at boot time.
Generated from the published advisory. Verify against your own configuration.
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 dataPhysical security controls (restricted facility access), disabling or password-protecting the HDMI debug/sys session interface, implementing secure boot with signed bootloader validation, and applying firmware updates if available from the vendor.
- Consultation4.0 h
- Implementation24.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $13,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-4874 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2013-4874 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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