dbcve.org
Ios XeOperating system · Cisco

CVE-2023-20235

HIGH · 8.8 CVSS v3.1 Published 2023-10-04
Fix available
A fix is available. Upgrade to 17.3.1 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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 on-device application development workflow feature for the Cisco IOx application hosting infrastructure in Cisco IOS XE Software could allow an authenticated, remote attacker to access the underlying operating system as the root user. This vulnerability exists because Docker containers with the privileged runtime option are not blocked when they are in application development mode. An attacker could exploit this vulnerability by using the Docker CLI to access an affected device. The application development workflow is meant to be used only on development systems and not in production systems.

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 vulnerability in Cisco IOS XE IOx application hosting infrastructure's on-device application development workflow allows authenticated remote attackers to gain root access to the underlying OS. The issue stems from Docker containers with privileged runtime option not being blocked during application development mode, enabling container escape via Docker CLI.

MitigationDisable the application development workflow feature in production environments. If development features are required, isolate affected systems from production networks and implement additional access controls. Cisco explicitly states this feature should only be used on development systems, not production.

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
Ios XeOperating system
Affected:< 17.3.1

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

CVSS:3.1/AV:N/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 IOS XE version
    Run 'show version' or 'show version | include IOS' to display the installed IOS XE version number
    Affected if The version is earlier than 17.3.1 (e.g., 17.2.x, 17.1.x, 16.x releases)
  2. Verify if IOx is enabled
    Run 'show iox' or 'show iox-service' to check if the IOx application hosting infrastructure is active on the device
    Affected if IOx is enabled and running (the 'IOx' service shows as 'Enabled' or 'Active')
  3. Confirm application development mode status
    Check the IOx configuration with 'show running-config | include iox' or 'show iox-app-hosting' to see if development-related features are configured
    Affected if Application development mode or the IOx app-hosting feature is enabled on the system
  4. Assess network exposure
    Review device access control lists, management interface configurations, and whether the device management IP is exposed to untrusted networks
    Affected if The device management or IOx interfaces are reachable from networks accessible to unauthenticated or low-privilege attackers

The system is affected if it runs IOS XE version < 17.3.1 with IOx application hosting enabled and exposed to network access, allowing an authenticated attacker to leverage the development workflow for container escape.

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
Upgrade available Upgrade to 17.3.1 or later
Fixed in 17.3.1
Interim mitigation

Disable the application development workflow feature in production environments. If development features are required, isolate affected systems from production networks and implement additional access controls. Cisco explicitly states this feature should only be used on development systems, not production.

Recommended fix High confidence

IOS XE 17.3.1 or later

  1. Confirm current IOS XE version using 'show version' command
  2. Download IOS XE 17.3.1 or later from Cisco.com or Cisco Software Central
  3. Review Cisco upgrade documentation for your specific hardware platform
  4. Perform firmware upgrade following standard Cisco IOS XE upgrade procedures
  5. After upgrade, verify the IOx application hosting infrastructure is updated and the vulnerability is patched
  6. If IOx application development mode is not needed in production, disable it using the 'iox' configuration commands

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

Fix this in Ios Xe Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,980
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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-2023-20235 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data