dbcve.org
AndroidOperating system · Google

CVE-2021-0918

HIGH · 8.8 CVSS v3.1 Published 2021-12-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
93/100
Remediation priority · Urgent
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
In gatt_process_notification of gatt_cl.cc, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution over Bluetooth with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-197536150

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 missing bounds check in the gatt_process_notification function of the Bluetooth GATT client (gatt_cl.cc) allows an out-of-bounds write, enabling remote code execution over Bluetooth without user interaction. The vulnerability affects Android-12 and exists in how the notification handling processes incoming data.

MitigationApply the vendor-supplied Android security patch for CVE-2021-0918 (Android-12 security update). As this is a Bluetooth stack vulnerability with RCE potential, immediate patching is critical.

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:= 12.0

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

CVSS:3.1/AV:A/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. Verify Android version is exactly 12.0
    Go to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADB shell
    Affected if The version shown is 12.0 (not 12L, 13, 14, or other versions)
  2. Check installed security patch level
    Go to Settings > About Phone > Security patch level, or run 'getprop ro.build.version.security_patch' via ADB shell
    Affected if The patch level is earlier than the Android 12.0 security update that addresses CVE-2021-0918 (specific patch date varies by carrier/device)
  3. Confirm Bluetooth is enabled
    Check Settings > Bluetooth, or run 'settings get global bluetooth_on' via ADB shell
    Affected if Bluetooth is turned ON - the GATT client notification handling code is only exercised when Bluetooth is active
  4. Identify if Bluetooth GATT client is in use
    Monitor Bluetooth activity via developer options or check if any app uses Bluetooth GATT (BLE) services - the vulnerability triggers when processing incoming notifications
    Affected if Any BLE peripheral is connected or notification data is being received by the Android device

A device is affected if it runs Android 12.0 exactly with a pre-patch security level AND has Bluetooth enabled, as the vulnerability lies in the gatt_process_notification function handling incoming GATT notifications.

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 vendor-supplied Android security patch for CVE-2021-0918 (Android-12 security update). As this is a Bluetooth stack vulnerability with RCE potential, immediate patching is critical.

Recommended fix Moderate confidence

Latest Android 12 security update (check Android Security Bulletins for specific patch level containing A-197536150)

  1. 1. Check the current Android security patch level on the affected device by navigating to Settings > About Phone > Android version or Settings > Security > Security update
  2. 2. Identify the Android 12 security update that addresses CVE-2021-0918 by checking the Android Security Bulletin for the month following the vulnerability disclosure
  3. 3. Apply the latest Android 12 security update to the device to obtain the fix for the out-of-bounds write in gatt_process_notification
  4. 4. Verify the security patch level has been updated after applying the update

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

Fix this in Android Scoped from the published advisory
  • Consultation6.0 h
  • Implementation4.0 h
  • Testing12.0 h
  • Review / QA6.0 h
28.0 hours of engineering $4,800
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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-2021-0918 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