CVE-2021-30331
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 data validation of external commands sent via DIAG interface in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, 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 confidenceBuffer overflow vulnerability in the DIAG (diagnostic) interface of Qualcomm Snapdragon chipsets. The flaw allows malformed external commands to cause a buffer overflow due to improper input validation, potentially enabling memory corruption.
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
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
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 Qualcomm chipset or firmware component in useDetermine if the system contains one of the affected Qualcomm components: Ar8035, Fsm10055, Fsm10056, Mdm9150, Mdm9650, Qca6174a, Qca6390, or Qca6391. Consult system hardware information, device documentation, or firmware inventory.Affected if The system uses any of the listed Qualcomm firmware components.
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Verify the firmware versionRetrieve the installed firmware version for the identified Qualcomm component through device diagnostics, firmware management interface, or system information utilities provided by the device manufacturer.Affected if Any version of the affected firmware is installed, since all versions are vulnerable.
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Confirm DIAG diagnostic interface is enabledCheck whether the DIAG (diagnostic) interface is active on the system. This may be exposed via serial debug ports, diagnostic services, or network services that provide diagnostic access to the chipset. Consult device documentation for diagnostic interface status.Affected if The DIAG interface is accessible or enabled, creating the attack surface for the buffer overflow.
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Inspect DIAG interface configurationReview configuration settings, service definitions, or network exposure settings related to the diagnostic interface. Look for any exposed DIAG endpoints, ports, or debug services that accept external commands.Affected if The DIAG interface accepts external commands or is exposed to untrusted inputs.
A system is affected if it contains any of the listed Qualcomm firmware components (Ar8035, Fsm10055, Fsm10056, Mdm9150, Mdm9650, Qca6174a, Qca6390, Qca6391) AND has the DIAG interface enabled or accessible, since all firmware versions contain the vulnerability.
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 vendor-supplied firmware patches from Qualcomm; device manufacturers should integrate and deploy the updated Snapdragon firmware to affected products.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30331 — 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-2021-30331 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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