CVE-2023-21040
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 buildCommand of bluetooth_ccc.cc, there is a possible out of bounds write due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-238420277References: 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 · high confidenceAn out-of-bounds write vulnerability exists in the buildCommand function of bluetooth_ccc.cc in Android's Bluetooth stack due to a logic error. This allows a local attacker to escalate privileges without requiring user interaction or additional execution privileges.
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 dataall versionsCVSS 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
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Confirm device is AndroidCheck the device operating system. On the device, go to Settings > About Phone > Software Information, or run 'getprop ro.build.version.release' via ADB to verify the OS is Google Android.Affected if The device is not running Google Android OS - this CVE affects only Android devices.
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Check Android security patch levelOn the device, go to Settings > About Phone > Security Patch Level, or run 'getprop ro.build.version.security_patch' via ADB. This displays the date of the installed Android security update.Affected if The security patch level is earlier than the patch that addresses CVE-2023-21040, meaning the vulnerability has not been mitigated.
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Verify Bluetooth component version (if accessible)Check the Bluetooth stack version if exposed in device settings or via 'dumpsys bluetooth_manager' or 'getprop bluetooth.version' via ADB. The vulnerability exists in the buildCommand function of bluetooth_ccc.cc in the Bluetooth stack.Affected if The Bluetooth stack version corresponds to an unpatched Android version, indicating the vulnerable code is present.
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Determine if Bluetooth has been usedReview Bluetooth connection history or check if Bluetooth is currently enabled on the device. The vulnerable code path in buildCommand function is exercised when Bluetooth is used.Affected if Bluetooth has been enabled or used on the device, triggering the vulnerable code path in the Bluetooth stack.
A user is affected if the device runs Android with a security patch level that predates the fix for CVE-2023-21040 and has Bluetooth enabled or has used Bluetooth, as the vulnerability resides in the buildCommand function of bluetooth_ccc.cc in the Android Bluetooth stack.
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.
From vendor dataApply the Android security patch for CVE-2023-21040; organizations should ensure all managed Android devices receive available platform security updates.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-21040 — 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-2023-21040 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
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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
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