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iOSOperating system · Cisco

CVE-2019-12672

MEDIUM · 6.8 CVSS v3.1 Published 2019-09-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
73/100
Remediation priority · Elevated
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
A vulnerability in the filesystem of Cisco IOS XE Software could allow an authenticated, local attacker with physical access to an affected device to execute arbitrary code on the underlying operating system (OS) with root privileges. The vulnerability is due to insufficient file location validation. An attacker could exploit this vulnerability by placing code in a specific format on a USB device and inserting it into an affected Cisco device. A successful exploit could allow the attacker to execute the code with root privileges on the underlying OS of the affected device.

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 confidence

A local privilege escalation vulnerability in Cisco IOS XE Software's USB file handling allows an authenticated attacker with physical device access to execute arbitrary code with root privileges by placing specially crafted files on a USB device and inserting it into an affected Cisco device. The vulnerability stems from insufficient validation of file locations in the filesystem.

MitigationApply the Cisco security patch for this vulnerability; until then, restrict physical access to network devices and enforce strict USB device policies. Monitor for unauthorized physical access attempts.

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
iOSOperating system
Affected:= 16.9.1

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

CVSS:3.1/AV:P/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 the installed Cisco IOS XE version
    Run 'show version' or 'show version | include Version' on the device CLI to retrieve the exact IOS XE version number
    Affected if The displayed version is exactly 16.9.1 (exact match required)
  2. Verify USB interface status
    Run 'show usb status' or 'show controller usb' to check if USB ports and USB file handling are enabled on the device
    Affected if USB interfaces are enabled/online - the vulnerability requires USB to be functional for the attack vector
  3. Confirm USB port hardware presence
    Inspect the physical device for available USB ports or use 'show inventory' to list hardware components including USB modules
    Affected if The device has USB ports physically present and operational - without USB hardware, the attack cannot be executed
  4. Check current user authentication status
    Review logged-in users and privilege levels using 'show users' and verify administrator credentials are not compromised
    Affected if An authenticated user with physical access exists - the attacker must be authenticated on the device to exploit the vulnerability

You are affected only if your device runs exactly Cisco IOS XE version 16.9.1, has USB functionality enabled/available, and an attacker could gain authenticated physical access to insert a specially crafted USB file.

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 Cisco security patch for this vulnerability; until then, restrict physical access to network devices and enforce strict USB device policies. Monitor for unauthorized physical access attempts.

Fix this in iOS Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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Scan for this in your stack

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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-2019-12672 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