dbcve.org
AndroidOperating system · Google

CVE-2018-9401

HIGH · 7.8 CVSS v3.1 Published 2025-01-18
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
In many locations, there is a possible way to access kernel memory in user space due to an incorrect bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

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 kernel-level vulnerability exists where incorrect bounds checking in multiple code locations allows user space processes to access kernel memory. This enables local privilege escalation without requiring any additional execution privileges or user interaction.

MitigationApply the relevant kernel/OS security patches to address the bounds check errors. This typically involves updating the kernel version or applying vendor-supplied patches.

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
AndroidOperating 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 running kernel version
    Run `uname -r` or `uname -a` on the Android device (via ADB shell or terminal emulator) to obtain the kernel version string
    Affected if The kernel version is earlier than the version that includes the CVE-2018-9401 fix (for Android, this is typically incorporated in the October 2018 security patch level or later) and does not contain the bounds-checking corrections in the kernel memory management code
  2. Check the Android security patch level
    On the Android device, go to Settings > About Phone > Security patch level, or run `getprop ro.build.version.security_patch` via ADB shell to retrieve the installed security patch date
    Affected if The security patch level is earlier than October 2018, indicating the device has not received the kernel-level fixes for this vulnerability
  3. Verify kernel source includes bounds-checking fixes
    If you have access to the kernel source or config, search for commits or code changes related to bounds checking in memory management functions (specifically in kernel memory access paths), or check the kernel config for CONFIG_DEBUG_KMEMLEAK or similar memory debugging features that may indicate awareness of the issue
    Affected if The running kernel is a mainline or vendor-supplied build without the specific bounds-checking corrections applied to prevent user-to-kernel memory access
  4. Confirm privilege escalation exposure
    Attempt to reproduce the vulnerability condition locally using a proof-of-concept that triggers the incorrect bounds check (if safe and authorized in your testing environment), or review system logs for any unauthorized kernel memory access attempts
    Affected if The system allows a local unprivileged process to read or write to kernel memory addresses due to missing bounds validation

A device is affected if it runs an unpatched Android kernel (security patch level before October 2018) that lacks the bounds-checking corrections preventing user space to kernel memory access.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant kernel/OS security patches to address the bounds check errors. This typically involves updating the kernel version or applying vendor-supplied patches.

Recommended fix Moderate confidence

Android devices should be updated to at least the September 2018 security patch level (2018-09-01 or later) which addresses CVE-2018-9401

  1. 1. Go to Settings > Security & Privacy > Security update on your Android device
  2. 2. Check the current Android security patch level
  3. 3. If the patch level is earlier than the September 2018 security update, apply the available system update
  4. 4. Navigate to Settings > System > Software Update (or Settings > About Phone > Software Update)
  5. 5. Download and install any available updates
  6. 6. After updating, verify the security patch level reflects the September 2018 patch or later
  7. 7. For enterprise or managed devices, contact your device administrator or mobile device management (MDM) provider for update deployment
Caveat Ensure compatible apps and services after updating; some legacy apps may not function on newer Android versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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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-2018-9401 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