CVE-2021-0925
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 · uneditedIn rw_t4t_sm_detect_ndef of rw_t4t.cc, there is a possible out of bounds read due to an incorrect bounds check. This could lead to remote information disclosure due to a limited change in behavior based on the out of bounds data with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-191444150
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 confidenceAn out-of-bounds read vulnerability exists in the Android NFC stack (rw_t4t.cc) within the rw_t4t_sm_detect_ndef function. The issue stems from an incorrect bounds check that allows reading memory outside the intended buffer, potentially exposing limited sensitive information. This occurs during NFC Tag Type 4 detection operations.
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= 12.0CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
-
Verify Android version is 12.0Go to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADBAffected if The device runs Android version 12.0 exactly (not 12.1, 11, or other versions)
-
Confirm NFC capability is presentCheck if the device has NFC hardware via Settings > Connected devices > NFC, or run 'getprop ro.hardware.nfc' via ADBAffected if The device lacks NFC hardware entirely (the vulnerability cannot be triggered)
-
Determine if NFC is enabledCheck NFC toggle status in Settings > Connected devices > NFC, or run 'cmd nfc get-state' via ADBAffected if NFC is turned ON - the vulnerable code path in rw_t4t_sm_detect_ndef can be triggered when the device attempts to read NFC Tag Type 4
-
Identify custom NFC implementationsFor organizations with custom Android builds: review source code in external/libnfc-nci/src/rw_t4t.cc for the rw_t4t_sm_detect_ndef function and verify bounds checking logic around NDEF message parsingAffected if Custom NFC code contains the same flawed bounds check pattern as the upstream vulnerability
A device is affected if it runs Android 12.0, has NFC hardware, and has a security patch level earlier than November 2021 with NFC enabled.
Generated from the published advisory. Verify against your own configuration.
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 · scopedApply the Android-12 security patch (November 2021 or later). For organizations with custom NFC implementations, review and correct bounds checking logic in NFC tag processing code.
Android 12 with December 2021 security patch level (2021-12-05) or later, or upgrade to Android 13
- Go to Settings > System > System Update on the Android device
- Check for and install any available system updates
- Ensure the installed security patch level is December 2021 (2021-12-05) or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-0925 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-0925 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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.
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.
- 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