CVE-2021-38783
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 · uneditedThere is a Out-of-Bound Write in the Allwinner R818 SoC Android Q SDK V1.0 camera driver "/dev/cedar_dev" through iotcl cmd IOCTL_SET_PROC_INFO and IOCTL_COPY_PROC_INFO, which could cause a system crash or EoP.
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 confidenceOut-of-bounds write vulnerability in the Allwinner R818 SoC camera driver (/dev/cedar_dev) that can be triggered through ioctl commands IOCTL_SET_PROC_INFO and IOCTL_COPY_PROC_INFO, allowing a local attacker to corrupt memory, crash the system, or elevate 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 data= 1.0CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Identify the SoC hardware platformCheck system information or device tree to determine if the system uses the Allwinner R818 SoC (e.g., check /proc/cpuinfo, /sys/devices/soc0/soc_id, or board documentation)Affected if The system is built on the Allwinner R818 SoC platform
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Verify the Android Q SDK versionCheck the Android SDK version installed on the system (typically found in build properties such as /system/build.prop or via getprop ro.build.version.sdk)Affected if The SDK version is exactly 1.0 (Allwinnertech Android Q Sdk version 1.0)
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Confirm the cedar_dev device existsCheck for the presence of /dev/cedar_dev device file (ls -la /dev/cedar_dev)Affected if The device file /dev/cedar_dev exists on the system
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Verify driver accessibilityCheck the permissions on /dev/cedar_dev (ls -la /dev/cedar_dev) and determine if the process has access to issue ioctl callsAffected if The device is readable/writable by the user or group that the potential attacker belongs to, enabling them to invoke IOCTL_SET_PROC_INFO or IOCTL_COPY_PROC_INFO commands
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Identify vulnerable ioctl command supportInspect the camera driver module or associated userspace libraries to confirm that ioctl commands IOCTL_SET_PROC_INFO and IOCTL_COPY_PROC_INFO are implemented and exposed (may require driver source review or checking /sys/class/video4linux for camera driver details)Affected if The cedar_dev driver exposes and accepts the IOCTL_SET_PROC_INFO or IOCTL_COPY_PROC_INFO ioctl commands
The environment is affected if it uses the Allwinner R818 SoC with Android Q SDK version 1.0 and has the /dev/cedar_dev device with the vulnerable ioctl commands accessible to the potential attacker.
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 vendor patch for the R818 Android Q SDK V1.0 to fix bounds checking in the cedar_dev driver; if no patch available, restrict access to /dev/cedar_dev or disable the camera driver until a fix is released.
- Consultation4.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-38783 — 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-2021-38783 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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