dbcve.org
Apq8096au FirmwareOperating system · Qualcomm

CVE-2021-35115

HIGH · 7.8 CVSS v3.1 Published 2022-04-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
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
Improper handling of multiple session supported by PVM backend can lead to use after free in Snapdragon Auto, 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 use-after-free vulnerability exists in the PVM (Paravirtual Machine) backend's session handling logic when multiple sessions are active. The improper handling of these concurrent sessions causes memory to be freed while still being referenced, leading to potential code execution or system compromise.

MitigationApply vendor-specific firmware patches from Qualcomm and device OEMs. As this is a chipset-level vulnerability in embedded systems, users should rely on OEM security update channels.

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
Apq8096au FirmwareOperating system
Affected:all versions
Ar6003 FirmwareOperating system
Affected:all versions
Mdm8215 FirmwareOperating system
Affected:all versions
Mdm8215m FirmwareOperating system
Affected:all versions
Mdm8615m FirmwareOperating system
Affected:all versions
Mdm9215 FirmwareOperating system
Affected:all versions
Mdm9310 FirmwareOperating system
Affected:all versions
Mdm9615 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
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 checks

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

  1. Identify the Qualcomm chipset model
    Retrieve the chipset identifier from the system using commands such as 'cat /proc/cpuinfo', 'lspci', 'dmesg', or by checking device documentation or bootloader logs. Look for identifiers matching the affected list: Apq8096au, Ar6003, Mdm8215, Mdm8215m, Mdm8615m, Mdm9215, Mdm9310, or Mdm9615.
    Affected if The chipset matches any of the affected Qualcomm models listed in the CVE.
  2. Confirm firmware version
    Query the firmware version using vendor-specific tools or by reading firmware metadata from /proc, /sys, or through AT commands on modem interfaces. Examples: 'cat /proc/firmware_version', 'AT+GMR' for Qualcomm modems, or check OEM diagnostic interfaces.
    Affected if Firmware is present on any of the listed affected chipsets, as all versions are vulnerable.
  3. Verify PVM backend is in use
    Check if the Paravirtual Machine (PVM) backend feature is enabled on the system. This may be visible in hypervisor configuration files, kernel boot parameters, or system logs. Look for references to 'PVM', 'paravirtual', 'pvvm', or similar virtualization modules in /proc/cmdline, dmesg output, or virtualization configuration files.
    Affected if PVM backend functionality is active or configured on the system.
  4. Check for active session handling
    Monitor or inspect the system for active concurrent sessions managed by the PVM backend. Review session logs, check for multiple simultaneous VM instances, or examine session management tables in /proc or /sys filesystems related to virtualization or paravirtual machine contexts.
    Affected if Multiple concurrent sessions are being handled by the PVM session management logic.

The system is affected if it runs any of the listed Qualcomm chipset firmware and has the PVM backend enabled with active concurrent session handling, as the use-after-free flaw exists in all versions of these specific firmware implementations.

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-specific firmware patches from Qualcomm and device OEMs. As this is a chipset-level vulnerability in embedded systems, users should rely on OEM security update channels.

Fix this in Apq8096au Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,960.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-35115 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-35115 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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