CVE-2021-30333
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 · uneditedImproper validation of buffer size input to the EFS file can lead to memory corruption in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wearables
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 confidenceImproper validation of buffer size inputs when processing EFS (Encrypted File System) files on Qualcomm Snapdragon chipsets leads to memory corruption. This is a classic input validation vulnerability where insufficient bounds checking on buffer size parameters allows out-of-bounds memory access during file 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 dataall versionsall versionsall versionsall versionsall versionsall versionsall versionsall 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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Identify the chipset modelCheck the processor/chipset information on the device. On Linux-based embedded devices, this can typically be found in /proc/cpuinfo, or via commands like 'cat /proc/cpuinfo', 'lspci', or checking device tree files in /sys/firmware/devicetree/base/modelAffected if The chipset model matches one of: Apq8009w, Apq8017, Apq8053, Apq8096au, Aqt1000, Ar8035, Csrb31024, or Mdm8207
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Confirm firmware versionRetrieve the firmware version of the Qualcomm chipset. This is often accessible via /proc/version, through manufacturer-specific diagnostic interfaces, or via AT commands on cellular-enabled devices. Consult device vendor documentation for the specific method.Affected if The firmware version can be retrieved at all - the advisory indicates all versions of the listed products are affected
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Verify EFS processing capabilityCheck if the device has EFS (Encrypted File System) functionality enabled or accessible. On Qualcomm-based devices, EFS partitions are typically mounted at /efs or similar paths. Verify if this filesystem is present and accessible on the device.Affected if The device supports and mounts EFS partitions, as the vulnerability triggers during EFS file processing operations
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Check for memory corruption indicatorsReview system logs (dmesg, kernel logs, vendor-specific logs) for memory corruption errors, out-of-bounds memory access warnings, or unexpected crashes during file operations involving encrypted storage. Look for patterns like 'buffer overflow', 'out of bounds', or 'memory corruption' in log outputs.Affected if Memory corruption events or unexpected crashes occur during file operations, particularly involving encrypted file system access
A device is affected if it contains any of the listed Qualcomm chipset models (Apq8009w, Apq8017, Apq8053, Apq8096au, Aqt1000, Ar8035, Csrb31024, Mdm8207) and utilizes EFS file processing capabilities.
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 dataThis firmware-level vulnerability requires patches from Qualcomm followed by device manufacturer updates. Users should apply security updates from their device vendors as they become available. Given the breadth of affected product lines (Auto, Compute, Connectivity, Consumer IOT, Industrial IOT, Mobile, Voice & Music, Wearables), comprehensive testing across device models is critical.
- Consultation8.0 h
- Implementation16.0 h
- Testing24.0 h
- Review / QA12.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30333 — 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-2021-30333 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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