dbcve.org
AndroidOperating system · Google

CVE-2021-0930

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 phNxpNciHal_process_ext_rsp of phNxpNciHal_ext.cc, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution over NFC with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-12 Android-9Android ID: A-181660091

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 memory corruption vulnerability exists in the Android NFC stack (NXP NCI HAL) where the phNxpNciHal_process_ext_rsp function in phNxpNciHal_ext.cc lacks proper bounds checking when processing extended NFC responses. This missing validation allows an attacker to write data beyond allocated buffer boundaries, potentially achieving remote code execution without requiring any user interaction or elevated privileges.

MitigationApply the Android security patch for CVE-2021-0930 (December 2021 bulletin). For custom implementations, add explicit length validation and bounds checking before buffer operations in the affected function to ensure response data fits within allocated buffers.

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:= 9.0= 10.0= 11.0= 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. Check Android OS version
    Go to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via adb shell
    Affected if The version is 9.0, 10.0, 11.0, or 12.0 exactly (not later security patch levels)
  2. Verify NFC is enabled
    Check Settings > Connected devices > NFC is turned on, or run 'nfc get-state' via adb shell
    Affected if NFC is enabled on the device - the vulnerability only triggers when NFC processes extended responses
  3. Confirm NXP NCI HAL is in use
    Check for the presence of the affected library file 'libnxp_nci_hal.so' in /vendor/lib/ or /system/lib/ via adb shell with 'find / -name libnxp_nci_hal.so 2>/dev/null'
    Affected if The NXP NCI HAL library exists on the device - this indicates the vulnerable component is present
  4. Check installed NFC firmware version
    Query NFC firmware details via 'dumpsys nfc' or check /vendor/etc/nfc/nfc_xxx.conf for version strings
    Affected if Unable to determine NFC firmware version from vendor - may indicate unpatched NCI HAL implementation

A device is affected if it runs Android 9.0-12.0, has NFC enabled, and uses the NXP NCI HAL implementation containing the vulnerable phNxpNciHal_process_ext_rsp function.

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 for CVE-2021-0930 (December 2021 bulletin). For custom implementations, add explicit length validation and bounds checking before buffer operations in the affected function to ensure response data fits within allocated buffers.

Recommended fix High confidence

Android-12L (API 32) or later with January 2022 Security Patch Level; for Android 9-12 devices, install the January 2022 monthly security update

  1. 1. Go to Settings on the Android device
  2. 2. Navigate to System > System Update (or Settings > About Phone > Software Update on some devices)
  3. 3. Check for and install any available system updates
  4. 4. Ensure the device receives the January 2022 Android Security Patch Level (SPL) or later
  5. 5. After update, verify the Android Security Patch Level is 2022-01-01 or newer in Settings > About Phone > Security Patch Level
Caveat Standard monthly security update with no expected breaking changes to normal device functionality

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

Fix this in Android Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,416.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-0930 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-0930 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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