dbcve.org
AndroidOperating system · Google

CVE-2023-21076

MEDIUM · 6.7 CVSS v3.1 Published 2023-03-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
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 createTransmitFollowupRequest of nan.cpp, there is a possible out of bounds write due to a heap buffer overflow. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-261857623References: N/A

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 · moderate confidence

A heap buffer overflow vulnerability exists in the NAN (Neighbor Awareness Networking) component's createTransmitFollowupRequest function in nan.cpp. The issue is an out-of-bounds write that can be exploited locally to achieve privilege escalation from System execution privileges. The vulnerability resides in the Android kernel's NAN implementation.

MitigationApply the Android security patch that addresses CVE-2023-21076. This is a kernel-level vulnerability requiring a platform update rather than application-level remediation.

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:all versions

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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/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. Check Android Security Patch Level
    Go to Settings > About Phone > Security Patch Level. Compare the date to the fix release date for CVE-2023-21076.
    Affected if The Security Patch Level is earlier than the month the fix was released (vulnerability is present in unpatched systems)
  2. Verify NAN (Wi-Fi Aware) feature status
    Check if Wi-Fi Aware (NAN) is enabled on the device. On Android, go to Settings > Network & Internet > Wi-Fi > Wi-Fi Preferences > Wi-Fi Aware, or check via shell command: 'settings get secure wifi_aware_enabled'
    Affected if NAN/Wi-Fi Aware is enabled - the vulnerable code path is active only when this feature is turned on
  3. Confirm NAN service is running
    Run 'dumpsys' or check for nan (Neighbor Awareness Networking) related processes: 'ps -A | grep -i nan' or 'dumpsys connectivity | grep -i nan'
    Affected if The NAN service process is running - indicates the vulnerable component is instantiated in memory
  4. Check kernel version
    Run 'uname -r' or 'cat /proc/version' to identify the kernel version. Compare against known fixed kernel versions if available.
    Affected if Older kernel versions without the CVE-2023-21076 fix are in use

A device is affected if it has an unpatched Security Patch Level and has Wi-Fi Aware/NAN functionality enabled or actively running.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Android security patch that addresses CVE-2023-21076. This is a kernel-level vulnerability requiring a platform update rather than application-level remediation.

Recommended fix Moderate confidence

Latest available Android security patch level (monthly security update containing fix for CVE-2023-21076)

  1. Check for and install the latest Android security patch update on the device. Go to Settings > Security > Security update and ensure the device has the most recent patch level.
  2. For Google Pixel devices, ensure the device is running the latest monthly feature drop and security update from Settings > System > System update > Check for update.
  3. If the device manufacturer has released a security update containing the fix for Android ID A-261857623, apply that update immediately.
  4. For enterprise or managed devices, ensure mobile device management (MDM) policies are configured to enforce security patch updates.
  5. Verify the installed Android version includes the fix by checking Settings > About phone > Android security patch level - aim for the most recent available patch level.
Caveat Minimal risk - monthly security updates are cumulative and typically do not introduce breaking changes; however, always backup data before applying major updates.

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

Fix this in Android Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,760
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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-2023-21076 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