dbcve.org
Aqt1000 FirmwareOperating system · Qualcomm

CVE-2021-1903

MEDIUM · 5.3 CVSS v3.1 Published 2021-11-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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 · unedited
Possible denial of service scenario can occur due to lack of length check on Channel Switch Announcement IE in beacon or probe response frame in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer Electronics Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Voice & Music, Snapdragon Wired Infrastructure and Networking

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 · high confidence

A denial of service vulnerability exists in Qualcomm Snapdragon chipsets due to missing length validation on the Channel Switch Announcement (CSA) Information Element in beacon or probe response frames. An attacker can send malformed frames with improperly sized CSA IE to trigger the DoS condition.

MitigationApply Qualcomm firmware/security updates for affected Snapdragon platforms. Where patches are unavailable, implement network-level filtering to reject malformed beacon and probe response frames with invalid CSA IE length fields.

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
Aqt1000 FirmwareOperating system
Affected:all versions
Ar8031 FirmwareOperating system
Affected:all versions
Ar8035 FirmwareOperating system
Affected:all versions
Ar9380 FirmwareOperating system
Affected:all versions
Csr8811 FirmwareOperating system
Affected:all versions
Csra6620 FirmwareOperating system
Affected:all versions
Csra6640 FirmwareOperating system
Affected:all versions
Csrb31024 FirmwareOperating system
Affected:all versions

CVSS 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
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Qualcomm chipset model
    Check your device's hardware specifications, system information, or network adapter details to determine if the WiFi/Bluetooth module uses one of these models: Aqt1000, Ar8031, Ar8035, Ar9380, Csr8811, Csra6620, Csra6640, or Csrb31024. This may be listed in device manager, lspci, lsusb, or product documentation.
    Affected if The device contains any of these eight Qualcomm chipset models listed in the CVE affected products.
  2. Verify wireless functionality is enabled
    Confirm that the WiFi or Bluetooth adapter is powered on and active. On Linux, use commands like 'ip link show' or 'rfkill list' to check adapter status. On Windows, check Device Manager or network adapter status.
    Affected if The wireless adapter is enabled and capable of receiving beacon or probe response frames.
  3. Inspect wireless traffic for CSA Information Elements
    Use a packet capture tool (such as Wireshark or tcpdump) to monitor wireless traffic and inspect beacon frames and probe response frames for the presence of Channel Switch Announcement (CSA) Information Elements. Look for IE type 37 (CSA IE) in captured frames.
    Affected if The device receives wireless frames containing CSA IE, which is standard in many WiFi environments.
  4. Check firmware version if accessible
    Attempt to retrieve the firmware version of the Qualcomm wireless chipset. On Linux, this may be available via 'ethtool -i', 'iw dev', or files in /sys/class/net/. Document the exact firmware version string for comparison.
    Affected if Firmware version is 'all versions' as stated in the CVE, meaning any version of the listed chipsets is affected.

You are affected if your device uses any of the eight listed Qualcomm chipset models (Aqt1000, Ar8031, Ar8035, Ar9380, Csr8811, Csra6620, Csra6640, Csrb31024) with WiFi or Bluetooth functionality enabled, since all firmware versions of these chipsets lack proper CSA IE length validation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Qualcomm firmware/security updates for affected Snapdragon platforms. Where patches are unavailable, implement network-level filtering to reject malformed beacon and probe response frames with invalid CSA IE length fields.

Fix this in Aqt1000 Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA6.0 h
34.0 hours of engineering $5,940
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-1903 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data