dbcve.org
Apq8053 FirmwareOperating system · Qualcomm

CVE-2020-3635

HIGH · 7.8 CVSS v3.1 Published 2020-06-22
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
Stack based overflow If the maximum number of arguments allowed per request in perflock exceeds in Snapdragon Auto, Snapdragon Compute, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Wearables in APQ8053, APQ8096AU, APQ8098, MSM8909W, MSM8917, MSM8920, MSM8937, MSM8940, MSM8953, MSM8996AU, MSM8998, Nicobar, QCM2150, QCS605, QM215, Rennell, Saipan, SDM429, SDM429W, SDM439, SDM450, SDM630, SDM632, SDM636, SDM660, SDM670, SDM710, SDM845, SM6150, SM7150, SM8150, SM8250, SXR1130, SXR2130

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 stack-based buffer overflow vulnerability exists in the perflock driver within the Android kernel. When the number of arguments passed per request exceeds the maximum allowed limit, the buffer on the stack overflows, potentially allowing local privilege escalation or denial of service.

MitigationApply the vendor-supplied kernel patch for CVE-2020-3635, which adds proper bounds checking on argument counts in the perflock driver. Update affected devices to the latest Android security patch level.

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
Apq8053 FirmwareOperating system
Affected:all versions
Apq8096au FirmwareOperating system
Affected:all versions
Apq8098 FirmwareOperating system
Affected:all versions
Msm8909w FirmwareOperating system
Affected:all versions
Msm8917 FirmwareOperating system
Affected:all versions
Msm8920 FirmwareOperating system
Affected:all versions
Msm8937 FirmwareOperating system
Affected:all versions
Msm8940 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 device chipset
    Check /proc/cpuinfo or use 'getprop ro.hardware' or 'cat /sys/devices/soc0/hw_platform' to identify the Qualcomm chipset model
    Affected if The chipset matches Apq8053, Apq8096au, Apq8098, Msm8909w, Msm8917, Msm8920, Msm8937, or Msm8940
  2. Confirm the perflock driver is present
    Check if /sys/class/perflock or /dev/perflock exists, or look for 'perflock' in kernel config via /proc/config.gz
    Affected if The perflock driver is present and accessible on the device
  3. Check the kernel version
    Run 'uname -r' or check /proc/version to obtain the kernel version string
    Affected if The kernel version is older than the patched version for this CVE (specific patched versions vary by device)
  4. Verify the Android security patch level
    Run 'getprop ro.build.version.security_patch' to see the installed security patch date
    Affected if The security patch level is earlier than the CVE fix date (typically included in Android kernel security bulletins after discovery)
  5. Check for the vulnerability in the perflock driver
    Inspect the perflock driver source or binary for missing bounds checking on argument count; verify the fix by examining the perflock_ioctl handler for argument validation
    Affected if The perflock driver code lacks proper bounds checking on the number of arguments passed to perflock requests

A device is affected if it uses one of the listed Qualcomm chipsets and has not received the vendor kernel patch that adds bounds checking in the perflock driver.

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 the vendor-supplied kernel patch for CVE-2020-3635, which adds proper bounds checking on argument counts in the perflock driver. Update affected devices to the latest Android security patch level.

Fix this in Apq8053 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-2020-3635 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