dbcve.org
Ios XeOperating system · Cisco

CVE-2020-3393

HIGH · 7.8 CVSS v3.1 Published 2020-09-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
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 application-hosting subsystem of Cisco IOS XE Software could allow an authenticated, local attacker to elevate privileges to root on an affected device. The attacker could execute IOS XE commands outside the application-hosting subsystem Docker container as well as on the underlying Linux operating system. These commands could be run as the root user. The vulnerability is due to a combination of two factors: (a) incomplete input validation of the user payload of CLI commands, and (b) improper role-based access control (RBAC) when commands are issued at the command line within the application-hosting subsystem. An attacker could exploit this vulnerability by using a CLI command with crafted user input. A successful exploit could allow the lower-privileged attacker to execute arbitrary CLI commands with root privileges. The attacker would need valid user credentials to exploit this vulnerability.

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 privilege escalation vulnerability in Cisco IOS XE's application-hosting subsystem allows authenticated local attackers with lower-privileged credentials to execute arbitrary CLI commands as root. The flaw stems from incomplete input validation of CLI command payloads combined with improper RBAC enforcement within the application-hosting Docker container, enabling commands to escape the container and execute on the underlying Linux OS with root privileges.

MitigationApply the Cisco IOS XE security patch for this vulnerability. Until patched, restrict CLI access to the application-hosting subsystem to only trusted, high-privilege users and monitor for unauthorized privilege escalation 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
Ios XeOperating system
Affected:= 16.12.1

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

CVSS:3.1/AV:L/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 Cisco IOS XE version
    Execute 'show version' on the device and locate the IOS XE version string in the output
    Affected if The installed IOS XE version is exactly 16.12.1
  2. Determine if application-hosting is enabled
    Execute 'show app-hosting status' or 'show running-config | include app-hosting' to check if the application-hosting subsystem is configured
    Affected if Application-hosting is enabled and running on the device
  3. Verify RBAC configuration for application-hosting
    Execute 'show privilege' to check your current privilege level, then review the RBAC configuration for application-hosting commands using 'show running-config | include role'
    Affected if Lower-privileged users (below privilege level 15) have access to application-hosting CLI commands
  4. Inspect Docker container privileges
    If application-hosting is active, check container execution permissions using 'show app-hosting detailed <container-name>' or similar application-hosting inspection commands
    Affected if The application-hosting container has permissions that allow escape to the underlying Linux host OS
  5. Audit recent application-hosting command execution
    Review device logs and accounting records for application-hosting CLI commands executed by non-privileged users
    Affected if Lower-privileged accounts have executed application-hosting commands that could indicate exploitation attempts

The device is affected if it runs IOS XE version 16.12.1 AND the application-hosting subsystem is enabled with improper RBAC allowing lower-privileged users access to container commands.

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 IOS XE security patch for this vulnerability. Until patched, restrict CLI access to the application-hosting subsystem to only trusted, high-privilege users and monitor for unauthorized privilege escalation attempts.

Fix this in Ios Xe Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2020-3393 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
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