dbcve.org
Ar8035 FirmwareOperating system · Qualcomm

CVE-2021-35086

HIGH · 7.5 CVSS v3.1 Published 2022-06-14
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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 buffer over read due to improper validation of SIB type when processing a NR system Information message 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 confidence

A buffer over-read vulnerability exists in Qualcomm Snapdragon processors due to improper validation of System Information Block (SIB) types when processing NR (5G) system information messages. An attacker sending specially crafted NR system information messages could read beyond buffer boundaries, potentially exposing sensitive memory contents without triggering a crash.

MitigationApply vendor-supplied firmware/microcode updates from Qualcomm for affected Snapdragon components. Since this is a chipset-level vulnerability, device manufacturers must integrate the Qualcomm patch and distribute updates to end users.

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
Ar8035 FirmwareOperating system
Affected:all versions
Qca6390 FirmwareOperating system
Affected:all versions
Qca6391 FirmwareOperating system
Affected:all versions
Qca6421 FirmwareOperating system
Affected:all versions
Qca6426 FirmwareOperating system
Affected:all versions
Qca6431 FirmwareOperating system
Affected:all versions
Qca6436 FirmwareOperating system
Affected:all versions
Qca6574a 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
High

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

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

  1. Identify Qualcomm wireless chipset model
    Check system information or network adapter details to determine if the device uses an affected Qualcomm chipset (Ar8035, Qca6390, Qca6391, Qca6421, Qca6426, Qca6431, Qca6436, or Qca6574a). On Linux, this can be done with 'lspci | grep -i network' or 'iw list' for wireless adapters. On Windows, check Device Manager under Network Adapters.
    Affected if The device does not use one of the listed Qualcomm chipset models, then it is not affected by this specific CVE.
  2. Determine chipset firmware version
    Query the installed firmware version of the Qualcomm wireless chipset. On Linux, use 'ethtool -i <interface>' or check /lib/firmware/ for the specific firmware file. On embedded devices, check /proc/version or vendor-specific diagnostic interfaces.
    Affected if The firmware version is present but all versions of the listed chipsets are vulnerable until patched by Qualcomm. Compare your firmware version against any vendor patch releases.
  3. Verify 5G/NR capability is enabled
    Confirm whether the device has 5G/NR functionality active or available. Check if the wireless interface supports 5G bands (use 'iw list' or 'iw dev <interface> info' on Linux). On mobile devices, check the modem or baseband status.
    Affected if The vulnerability only applies when the device processes NR (5G) system information messages. If 5G/NR is completely disabled and the chipset never processes SIB messages for 5G, the attack surface may be reduced.
  4. Check for vendor firmware updates
    Check with the device manufacturer or system integrator for any firmware or microcode updates that address this CVE. Review vendor security advisories or release notes for the specific product model.
    Affected if No vendor patch has been applied to the Qualcomm chipset firmware, indicating the device remains vulnerable.

A device is affected if it uses any of the listed Qualcomm chipsets (Ar8035, Qca6390, Qca6391, Qca6421, Qca6426, Qca6431, Qca6436, Qca6574a) with unpatched firmware and has 5G/NR capability enabled, as the vulnerability lies in processing NR system information messages.

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 vendor-supplied firmware/microcode updates from Qualcomm for affected Snapdragon components. Since this is a chipset-level vulnerability, device manufacturers must integrate the Qualcomm patch and distribute updates to end users.

Fix this in Ar8035 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing24.0 h
  • Review / QA12.0 h
60.0 hours of engineering $10,240
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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-2021-35086 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