CVE-2021-30255
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 · uneditedPossible buffer overflow due to improper input validation in PDM DIAG command in FTM in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon 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 confidenceA buffer overflow vulnerability exists in the PDM DIAG command within Factory Test Mode (FTM) of Qualcomm Snapdragon chipsets. The issue stems from improper input validation, allowing an attacker to overflow a buffer by providing specially crafted input to the PDM DIAG command. This could lead to arbitrary code execution or 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 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 modelRetrieve the Qualcomm Snapdragon chipset identifier from the device firmware, bootloader, or system information (typically via `cat /proc/cpuinfo`, `AT+CGMM`, or OEM diagnostic tools)Affected if The chipset matches any of the following models: Apq8009, Apq8009w, Apq8017, Apq8037, Apq8053, Apq8096au, Aqt1000, or Ar8035
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Confirm Factory Test Mode (FTM) availabilityCheck whether FTM is accessible on the device. FTM is typically enabled via specific boot modes, diagnostic ports, or engineering access interfaces. Consult OEM documentation for the specific method to determine FTM status.Affected if Factory Test Mode is enabled or accessible on the device
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Verify DIAG command interface is exposedDetermine if the DIAG (diagnostic) command interface is active. This may be accessible through serial debug ports, USB diagnostic枚举, or specific AT command interfaces depending on the OEM implementation.Affected if The DIAG command interface is available or exposed (not disabled)
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Check PDM functionality exposureAssess whether the PDM (Pulse Density Modulation / Power Domain Manager) diagnostic commands are reachable through the DIAG interface. This typically requires access to the FTM diagnostic command set.Affected if PDM DIAG command functionality can be invoked through the diagnostic interface
A device is affected if it uses any of the listed affected chipset models AND has Factory Test Mode enabled with the DIAG command interface accessible, allowing the PDM DIAG command to be reached.
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 Qualcomm firmware updates for affected Snapdragon platforms. Until patches are available, restrict physical and adjacent access to FTM functions and disable diagnostic commands in production firmware.
- Consultation8.0 h
- Implementation16.0 h
- Testing24.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30255 — 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-2021-30255 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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