AndroidOperating system · Google

CVE-2023-21311

MEDIUM · 5.5 CVSS v3.1 Published 2023-10-30
Fix available
A fix is available. Upgrade to 14.0 or later.
See remediation →
57/100
Remediation priority · Elevated
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
In Settings, there is a possible way to control private DNS settings from a secondary user due to a permissions bypass. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.

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 permissions bypass in Android Settings allows a secondary user to control private DNS settings. This enables local information disclosure of network configuration details without requiring elevated privileges or user interaction.

MitigationApply the Android security patch level that addresses this vulnerability (Google's March 2023 Android Security Bulletin or later). Users should ensure their devices receive regular security updates.

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
AndroidOperating system
Affected:< 14.0

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
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/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. Check Android version
    Go to Settings > About Phone > Android version. Alternatively, run 'adb shell getprop ro.build.version.release'
    Affected if Version is below 14.0 (Android 14)
  2. Verify multiple user accounts exist
    Go to Settings > Users > Users list. Alternatively, run 'adb shell pm list users'
    Affected if More than one user account exists on the device (secondary user present)
  3. Check Private DNS setting accessibility
    Go to Settings > Network & Internet > Private DNS. Observe whether secondary user accounts can modify this setting without restrictions
    Affected if Secondary users can access and modify Private DNS settings
  4. Confirm security patch level
    Go to Settings > About Phone > Security patch level. Alternatively, run 'adb shell getprop ro.build.version.security_patch'
    Affected if Patch level is earlier than March 2023

Device is affected if running Android version below 14.0 AND has secondary user accounts, with a security patch level earlier than March 2023.

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 14.0 or later
Fixed in 14.0
Interim mitigation

Apply the Android security patch level that addresses this vulnerability (Google's March 2023 Android Security Bulletin or later). Users should ensure their devices receive regular security updates.

Recommended fix High confidence

Android 14.0

  1. Verify the current Android version on the device by navigating to Settings > About Phone > Android version
  2. Check if your device manufacturer has released Android 14.0 (or later) for your specific device model
  3. If Android 14.0 is available, back up important data on the device
  4. Initiate the system update through Settings > System > Software Update > Download and install
  5. Ensure the device is connected to Wi-Fi and has sufficient battery (recommended: 50% or more)
  6. Follow the on-screen prompts to complete the upgrade process
  7. After upgrade, verify the Settings > Network & Internet > Private DNS settings are properly controlled by the primary user only
Caveat Android 14 may introduce UI changes, deprecate certain APIs, or modify app behavior; review Android 14 release notes for compatibility considerations

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

Fix this in Android Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-21311 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-21311 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