CVE-2021-30343
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 integrity check can lead to race condition between tasks PDCP and RRC? after a valid RRC Command packet has been received in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile
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 confidenceRace condition vulnerability in Qualcomm Snapdragon chips where improper integrity check creates a timing window between PDCP (Packet Data Convergence Protocol) and RRC (Radio Resource Control) tasks after processing a valid RRC Command packet. This could allow manipulation of cellular protocol handling through the race condition.
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
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/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 baseband chipset modelOn mobile devices, check Settings > About Phone > Baseband or use 'AT+CGMR' AT command. For networking equipment, consult vendor hardware documentation or CLI outputs like 'lspci', 'lsusb', or manufacturer-specific commands.Affected if The chipset matches any of: Ar8035, Qca6390, Qca6391, Qca6426, Qca6436, Qca6574a, Qca6574au, or Qca6595au
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Verify firmware version if accessibleAttempt to retrieve firmware version via AT commands (for modems) or vendor management interface. Common commands: 'AT+GMR' or through the device's administrative console.Affected if Any firmware version is returned for the affected chipset models, since all versions are vulnerable
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Confirm device uses cellular baseband processingVerify the device has cellular/mobile network capability (4G/5G/3G) which uses the affected PDCP and RRC protocol stack.Affected if The device processes cellular radio protocols and uses a Qualcomm baseband processor
A device is affected if it contains any of the listed Qualcomm chipset models (Ar8035, Qca6390, Qca6391, Qca6426, Qca6436, Qca6574a, Qca6574au, Qca6595au) regardless of firmware version, since all versions of these chips have the race condition 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 dataThis is a firmware-level vulnerability in Qualcomm baseband/processor chips requiring a firmware update from Qualcomm to be distributed through device manufacturers. No user-configurable mitigation available.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30343 — 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-2021-30343 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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- 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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