CVE-2012-4221
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 · uneditedInteger overflow in diagchar_core.c in the Qualcomm Innovation Center (QuIC) Diagnostics (aka DIAG) kernel-mode driver for Android 2.3 through 4.2 allows attackers to execute arbitrary code or cause a denial of service via an application that uses crafted arguments in a local diagchar_ioctl call.
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 confidenceInteger overflow vulnerability in the Qualcomm DIAG kernel-mode driver (diagchar_core.c) for Android 2.3-4.2. The flaw exists in the ioctl handler where crafted arguments passed to diagchar_ioctl can trigger the overflow, allowing a local malicious application to escalate privileges to kernel level and execute arbitrary code or cause a denial of service.
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= 2.3= 2.3.1= 2.3.2= 2.3.3= 2.3.4= 2.3.5= 2.3.6= 2.3.7= 3.0= 3.1= 3.2= 3.2.1CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
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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Check Android versionRun 'getprop ro.build.version.release' or check Settings > About Phone > Android versionAffected if The version is 2.3.x (Gingerbread) or 3.x (Honeycomb) through 3.2.1, matching the affected range
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Confirm Qualcomm chipset presenceCheck /proc/cpuinfo for 'Qualcomm' or run 'getprop ro.hardware' to identify the device hardware platformAffected if The device uses a Qualcomm Snapdragon or other Qualcomm chipset, as the DIAG driver is Qualcomm-specific
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Verify diagchar driver presenceCheck for /dev/diag or /dev/diagchar device node, or look for 'diagchar' in /proc/modules if the driver is loaded as a moduleAffected if The DIAG character device exists, indicating the vulnerable driver interface is present and accessible
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Test ioctl interface accessibilityAttempt to access /dev/diag with appropriate permissions or check driver configuration in /sys/module/diagchar/parameters/Affected if The ioctl interface is available and not restricted, allowing direct communication with the driver
The environment is affected if running Android 2.3-3.2.1 on Qualcomm hardware with the DIAG driver present and accessible, as the integer overflow in diagchar_ioctl can then be triggered by a local application.
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 available Android/Qualcomm security patches via system firmware update. For custom Android builds, patch the diagchar_core.c driver to properly validate integer arguments before arithmetic operations and use safe integer handling functions.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-4221 — 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-2012-4221 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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- Version or environment caveats, and links to real fixes
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